A month ago, Rep. Jason Chaffetz, R-Utah, one of the most high-profile House Republicans, was so over this Congress thing.

"After more than 1,500 nights away from my home, it is time," he wrote in a Facebook post in April, surprising the political world by announcing his retirement. "I may run again for public office, but not in 2018."

Later, Chaffetz said he might not even finish his term, which ends in January 2019.

Some surmised that Chaffetz was ditching Congress because he decided it just wasn't fun anymore. As chairman of the House Oversight and Government Reform Committee, Chaffetz is in charge of investigating wrongdoing in the government. And it's more fun to investigate your political opponents' wrongdoing than the candidate you supported (somewhat) for president.

But now, there could be wrongdoing in the government, and the guy who had one foot out the door is suddenly all in again.

Hours after news broke Tuesday that President Donald Trump may have tried to intercede an FBI investigation into his then-national security adviser, Michael Flynn, and that a well-respected former FBI director had evidence, Chaffetz sent a letter to the FBI requesting all documentation. Here's part of that letter:

"According to, 'Mr. Comey created similar memos — including some that are classified — about every phone call and meeting he had with the president.' If true, these memoranda raise questions as to whether the President attempted to influence or impede the FBI's investigation as it relates to Lt. Gen. Flynn. So the Committee can consider that question, and others, provide, no later than May 24, 2017, all memoranda, notes, summaries, and recording referring or relating to any communications between Comey and the President."

Chaffetz didn't stop there. If the FBI doesn't hand this over willingly, Chaffetz indicated he'd be ready to force it with a subpoena.

"GOP oversight is going to get the Comey memo, if it exists. I need to see it sooner rather than later. I have my subpoena pen ready," he tweeted.

Gauntlet thrown. Now the rest of House Republicans have to decide if they'll side with Chaffetz that Congress should pursue what Trump allegedly told Comey, wherever the facts may lead. (And it's conceivable those facts could lead to a serious consideration about impeachment.) Or if they'll give Trump the benefit of the doubt.

Suddenly, Chaffetz is in the center of the action — where people who know him say he thrives. Suddenly, Congress is fun again even without Hillary Clinton's emails to investigate. And that's the likeliest reason Chaffetz just made himself the face of Congress's investigation into the possible act of obstruction by Trump just a month after giving up on Congress.

Chaffetz's staff confirmed to The Washington Post that he still plans to leave Congress, but they did not clarify whether he'd stay on until his committee's investigation is finished. Chaffetz's mindset, they said, is: He'll keep doing his job while he's in the job.

Chaffetz was never really a Trump guy. He ditched Trump after the "Access Hollywood" tapes, saying he couldn't defend that kind of person to his 15-year-old daughter. But in a jaw-dropping 180, a few weeks later, he said he'd vote for Trump:

"I will not defend or endorse @realDonaldTrump, but I am voting for him. HRC is that bad. HRC is bad for the USA."

Chaffetz's decision to reinsert himself into the role of oversight over Trump after declining to do much (to much criticism on the left) feels reminiscent of that late October "I will not defend or endorse, but I do support" moment he had. In each case, Chaffetz firmly decided to go down one track, then he abruptly changed his mind and did the exact opposite.

Why? Well, Chaffetz is a guy whose career appears to be almost singularly driven by ambition. He briefly ran for speaker of the House in 2015. He's more likely than not to run for governor of Utah in 2020.

In October, Chaffetz may well have been disgusted by what Trump said on a hot mic. But he soon calculated that at least voting for Trump, the Republican nominee for president, was a requisite to advancing in the Republican Party.

A month ago, Chaffetz calculated that staying in Congress was a political dud for his political future.

But now, Congress is in the midst of dealing with the biggest political news story in the United States right now, and Chaffetz has just injected himself right in the center of it.

Clearly, Chaffetz has calculated that being in Congress — this Congress — isn't so bad after all for a politically ambitious lawmaker.