The White House says President Trump fired James Comey because of how he handled the Hillary Clinton email investigation.

Let that sink in for a moment.

The president, who campaigned before crowds that chanted, "Lock her up," is telling the American people that he summarily fired the FBI director, by letter, because he went outside Department of Justice protocols in speaking out about the Clinton investigation months ago.

Trump's conclusion, the White House says, was based on a 2 1/2 page memo penned by Deputy Attorney General Rod Rosenstein. It's dated Tuesday. The recommendation was affirmed by Attorney General Jeff Sessions.

The president was asked by reporters at the White House on Wednesday why he fired Comey, and he said: "Because he wasn't doing a good job, simply. He was not doing a good job."

As soon as news of the termination broke, some political observers began to sound off that something doesn't add up. The timing is suspicious, and the reasoning is convenient. It raises all kinds of questions about what happened and what happens next, especially as the FBI is reportedly ramping up its investigation of Trump associates' connections to Russia.

Trump went on a tweetstorm about it Tuesday night and into Wednesday morning:

During the presidential campaign, though, Trump had varying reactions to Comey. Back then, he criticized Comey for not recommending that Clinton be criminally prosecuted.

Then he later praised the FBI director for having the "guts" to speak out just days before the election to say he was reopening the investigation into Clinton's emails. Trump said Comey should "hang tough." Clinton believes that move essentially elected Trump. Comey, just days ago, said it made him "mildly nauseous" to think he might have swung the election.

Never did Trump hint back then that Comey may have broken protocol or handled things inappropriately.

Now that Trump is president — and some of his associates apparently happen to be the focus of an FBI investigation — he believes Comey has to go.

On Tuesday evening, Trump's White House issued a 79-word statement. It said Comey had been "terminated." It said Trump "acted based on the clear recommendation of both Deputy Attorney General Rod Rosenstein and Attorney General Jeff Sessions." In a letter from Trump to Comey, also released by the White House, Trump mentions that Comey told him on three separate occasions that he was not the subject of the FBI's investigation before stating, "I nevertheless concur with the judgment of Department of Justice that you are not able to effectively lead the Bureau." Trump closed the letter by wishing Comey luck in his "future endeavors."

Comey was surprised by the firing. He reportedly first saw it on TV — perfect for the kind of reality TV drama that has played out already in this young Trump presidency.

A letter, informing Comey that he had been let go, was delivered to the FBI's Washington headquarters, but Comey wasn't there. He was at an FBI recruitment event in Los Angeles. He thought what he saw on TV was a prank, a joke.

It was no joke.

So Comey's out. But is there more to the story? And where does the FBI's investigation of Trump and Russia go from here? Here are some possible explanations — and questions moving forward:

The potential reasons

1. The FBI's ramped-up investigation: The timing of Comey's firing is suspicious because the FBI's Russia investigation was apparently heating up. CNN reported that Comey was fired shortly before federal prosecutors were about to break the news that new grand jury subpoenas were being issued related to the investigation. "The subpoenas represent the first sign of a significant escalation of activity in the FBI's broader investigation begun last July into possible ties between Trump campaign associates and Russia," CNN writes.

2. Michael Flynn — and Trump's judgment — had once again become top of the news: Trump's former national security adviser was a major focus of a congressional hearing Monday. Sally Yates, whom Trump fired as acting attorney general because she refused to defend Trump's travel ban, testified that she believed Flynn had been compromised with regard to the Russians. She said she warned White House counsel Don McGahn twice, showing him evidence that Flynn lied to the vice president about his conversations with the Russian ambassador — and, importantly, that could make him subject to blackmail.

The president did nothing.

Flynn served for 18 more days and was let go only after the Justice Department's warnings became public in the news media. Trump continued to defend Flynn, calling questions about him a "witch hunt," despite the fact that he is apparently at the center of the FBI's investigation.

It's also notable that Yates was fired days after speaking with McGahn, as was former U.S. Attorney Preet Bharara, who as Axios notes, was also investigating issues related to Trump and Russia. "What they have in common: They all were investigating Trump when they got fired, and there's a Russia thread in each of their cases," Axios' Shannon Vavra writes.

3. Comey disputing Trump: Comey just testified before Congress for the second time in two months. The first time, March 20, didn't go so well for Trump. That's when (1) Comey first publicly acknowledged an FBI investigation into Russia and Trump associates and (2) disputed Trump's tweeted allegation that President Barack Obama had wiretapped him. Comey said it didn't happen.

If there's one thing you don't do if you're hoping to curry favor with this president, it's disagree with him. Currying favor with the president, of course, is not the FBI director's job, but it's a delicate line. He serves at the pleasure of the president.

4. "Mildly nauseous": Comey just days ago said before Congress that it made him "mildly nauseous" to think he might have swung the election by coming out less than two weeks before Election Day to say he'd reopened the Clinton email investigation. That statement may have made this president mildly nauseous. No one has been more sensitive about the size of his victory than Trump, who has repeatedly — and sometimes falsely — touted his Electoral College totals.

On Tuesday, Comey may have given the president an opening to fire him. He admitted being mistaken when he testified before Congress when he said that Clinton aide Huma Abedin forwarded hundreds or thousands of emails to now-estranged husband Anthony Weiner's laptop. Comey corrected himself in a letter to Congress, saying he meant that they had been backed up not forwarded.

That, the White House may have believed, gave Trump cause to ax Comey, especially with the Rosenstein memo in hand.

But who believes that? Who believes that this president fired someone for being inartful with his language?

5. Comey got too big: The real reason may be that Comey got too ubiquitous, too visible, too big for Trump's liking. And no one can get too big in Trump's world.

Texas Rep. Blake Farenthold alluded to that on NPR's Morning Edition on Wednesday.

"The real issue is Comey had become the focus of everything," Farenthold said. "It wasn't about the FBI. His face was on TV way too much. How many former FBI directors beyond J. Edgar Hoover can you name? They work quietly and methodically in the background, doing their investigations. They're not on the front page of the newspaper, and they're not involved in elections."

Look at what happened with Nikki Haley, Trump's ambassador to the United Nations. Trump upbraided her, joking about the job she's doing and that he could fire her if he wanted to. Immediately preceding that, Haley was winning plaudits for her aggressiveness and being talked about as a potential 2024 presidential candidate.

She has scarcely been heard from since.

Trump creates warring power factions all around him. That means no one gets too big — and if they do, they are taken down a notch or ousted (see Bannon, Steve, as well).

It means, in his world, no one amasses enough power to speak independently without fear of reprisal from Trump.

Comey's firing is arguably a power play, sending a signal once again of who truly is the boss.

Questions for what happens next?

What happens now is the key — unanswerable — question. But let's explore some others that could inform this:

1. Who does Trump nominate? Trump had the authority to terminate Comey and the power to nominate another person to run the country's most powerful law enforcement agency. What kind of person does he appoint? Names like Rudy Giuliani and Chris Christie are being floated — or he could appoint someone less high-profile, someone who can't get too big and who will do the job quietly.

2. Will that person have ties to Trump's world in one way or another? Remember, there is a faction out of the New York area within FBI current and former circles who were suspected of leaking to Giuliani during the campaign.

3. What happens to the FBI's Russia investigation? Temporarily, presumably, the deputy director, Andrew McCabe, will run it. He is a 21-year veteran of the FBI. He joined as a special agent out of New York in 1996, focusing on organized crime. But Trump went after him during the campaign.

As NBC reminds, Trump falsely accused McCabe of the following in October: "It was just learned a little while ago that one of the closest people to Hillary Clinton, with longstanding ties to her and her husband, gave more than $675,000 to the campaign of the spouse of a top FBI official, his wife, who helped oversee the investigation into Mrs. Clinton's illegal email server."

He added the next day: "The man who was in charge of the investigation of Hillary Clinton accepted essentially from Hillary Clinton $675,000 that went to his wife."

Trump went on to connect the dots in a misleading way and accused Clinton of being a crook. The truth is that McCabe's wife was approached by Gov. Terry McAuliffe and Virginia Democrats to run for the state Senate. She did, and McAuliffe's political action committee as well as the state party unsurprisingly donated to her campaign. McAuliffe was a longtime fundraiser for the Clintons before becoming governor.

Jill McCabe lost. Andrew McCabe did not have any involvement in the Clinton email investigation at the time. Three months later, in February 2016, Andrew McCabe became deputy director of the FBI, the first time he had any oversight of the investigation, as PolitiFact noted.

4. How do congressional Republicans respond? The unintended consequence for Trump very well may be that calls for independent oversight, an independent investigation, grow. Republicans are questioning the decision. Richard Burr, the Senate Intelligence Committee chairman leading the Senate's Russia investigation, said he was "troubled" by the timing of the decision. (And Burr was an adviser to the Trump campaign.)

John McCain of Arizona said he was "disappointed" and added, "I have long called for a special congressional committee to investigate Russia's interference in the 2016 election. The president's decision to remove the FBI director only confirms the need and the urgency of such a committee."

Bob Corker of Tennessee, chairman of the Senate Foreign Relations Committee, said that Comey's "removal at this particular time will raise questions. It is essential that ongoing investigations are fulsome and free of political interference until their completion."

Majority Leader Mitch McConnell, however, said he was against an independent prosecutor or investigation. On the Senate floor Wednesday, he said a "new investigation would impede the current work" of the Senate's Intelligence Committee's ongoing Russia investigation.

5. How do Democrats respond? Democrat Sheldon Whitehouse's statement Tuesday night might be instructive as to the questions Democrats have. "America needs to have confidence that the Department of Justice will fill its traditional role of following the facts fearlessly, and prosecuting whomever has violated the law no matter the office they hold," he said.

Senate Democratic leader Chuck Schumer said Tuesday night that he told the president by phone, "You are making a big mistake" and that he wondered whether the investigation was "getting too close for the president."

On the Senate floor Wednesday, Schumer again called for Rosenstein to appoint an independent prosecutor.

Were the FBI's questions "getting too close to home for the president?" Schumer asked. He added, "If there was ever a time when circumstances warranted a special prosecutor, it was right now." He said the investigation needs to be "far away from the heavy hand of this administration."

Schumer told Democratic senators to be in their seats in the Senate chamber at 9:30 a.m. ET Wednesday to listen to what McConnell had to say.

McConnell whacked Democrats for "complaining about the removal of an FBI director they repeatedly criticized."

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