Last Friday, Sen. Ron Johnson gave Senate Republican leadership a minor aneurysm when he announced he wasn’t ready to back the health care bill.

Getting Johnson to support that bill was expected to be easy. He’s a committee chair and an ally of Paul Ryan, not known for being a troublemaker or a thorn in anyone’s side. But his hesitance played a role in the ultimate decision by Senate Republican Leader Mitch McConnell to postpone a vote on the effort to repeal the Affordable Care Act, which is now expected to take place after Congress returns from their July 4 recess.

Johnson’s announcement last week—along with three other lawmakers—surprised Washington insiders. But, according to Wisconsin Republican insiders, it shouldn’t have been.

After all, less than a year ago, those same Washington insiders left him for dead.

While the rest of the country was focused on the bruising presidential race last year, Johnson, a plastics company CEO-turned-senator, was locked in a re-election contest nobody expected him to win. For at least a year, the D.C. conventional wisdom held that no incumbent had a worse shot at getting re-elected than he did.

An especially painful sting came on Oct. 3, when Politico Pro broke the news that the National Republican Senate Committee—the powerful party arm aligned with Senate leadership and responsible for getting incumbents re-elected—had canceled its plans to spend $800,000 in the final weeks of the campaign on TV ads boosting Johnson.

An anonymous NRSC aide told the publication they needed to “adjust reservations and strategy” for the good of the party.

And that meant leaving Johnson to fend for himself.

Johnson took a more active role in campaign messaging after being slighted, according to people who know him, even writing some of his own ad copy. And he didn’t just win re-election; he won 70,000 more votes than Donald Trump did, meaning the White House wouldn’t be able to tell him that he only was re-elected because of Trump’s coattails effect.

A person who has discussed the NRSC’s move with Johnson after Election Day told The Daily Beast he believes the senator “is still mega-pissed about what McConnell and Leadership did to him during the Senate race.”

“This has been a long-stewing simmer for him, and after they cut him loose he was like, ‘Screw them, I owe them nothing,’” the source continued. “After the election, he made no secret of how pissed he was—he feels that he won that thing all on his own. They wrote him off for dead and cut all his money off.”

A Wisconsin Republican political operative who knows Johnson told The Daily Beast that he believes Johnson put the brakes on the health care bill because he genuinely believes it isn’t conservative enough, and not out of any lingering frustration with leadership. But that person added that having been abandoned by the NRSC and other Washington establishment insiders probably isn’t far from the senator’s mind these days.

“He was already left for dead,” the source said, “and when you’re left for dead and you keep walking, there’s a pretty remarkable level of strength that comes with that.”

He also noted that Johnson has promised he won’t run for a third term in the Senate—meaning political considerations won’t have much sway over his view of the bill.

“He’s a true free agent,” he noted. “He’s truly unchained here.”

When Johnson first announced his hesitance about the Senate bill, he was joined by Ted Cruz, Mike Lee, and Rand Paul—all Tea Party stalwarts who leadership expected would cause problems. Johnson was the outlier. And in part because of his willingness to make things difficult, leadership delayed a vote on the legislation.

Still, in the meantime, there are indications he won’t hold up the bill indefinitely and is looking for ways to get to “yes” on the legislation. Days after banding together with conservatives, Johnson has signaled he’s taken a step closer to supporting the bill. On CNN’s New Day on June 28, Johnson argued that the Congressional Budget Office’s estimate that 15 million people will lose health insurance in 2018 if the bill passes is based on bad information.

A Johnson aide told The Daily Beast this issue came up on Tuesday when Republican senators gathered for lunch to talk about the bill. They discussed the fact that the CBO’s estimate of how many people on the individual market who would lose health insurance is based on the number of people who were insured as individuals in March of 2016: 26 million people. But there’s new CBO data available calculating the number of people who have insurance through the individual markets in January of 2017: just 19 million (PDF).

Johnson learned about this at the lunch discussion. That afternoon, he had his staff do the math to compare the number of people who would have health insurance through the individual market in 2018 to the number in January of 2017. And his staff concluded it would be the same number of people: 19 million people. The CBO’s estimate—based on the March 2016 numbers—indicates 7 million fewer people would get health care on the individual market in 2018. Johnson now says that’s wrong, and he argues that 7 million fewer people would lose insurance than the CBO report says.

He emphasized it in an appearance on Morning Joe on Wednesday.

“That, from my standpoint, is big news,” he said, “because the distortion of the original CBO report—is just wrong, because it’s comparing against a very old baseline, a year and three month old information. And so that’s all I was asking for, guys, is we need more time, we need more information.”

Douglas Holtz-Eakin, former director of the CBO and head of the American Action Forum—who supports the Senate bill—told The Daily Beast Johnson makes a valid point, though his office’s work isn’t the equivalent of a full CBO analysis of the bill.

“It is better to use more recent information,” he said. “I doubt it is as complete an analysis as a CBO score, and so ‘better’ will be in the eye of the beholder.”

He said a full CBO analysis of the Senate bill based on the number of people with health insurance in January 2017 would be valuable. But the CBO isn’t going to do that because they started their analysis of the House’s health care bill before the January 2017 number was public.

“It’s a shame,” Holtz-Eakin said.

In the meantime, he said Johnson’s math is interesting.

“It’s obviously a big deal to Sen. Johnson,” Holtz-Eakin said.  

And Johnson has indicated this changes how he views the bill. He told CNN’s New Day on Wednesday that it’s “big news in terms of the debate.”

That all means the Badger State senator may be moving toward backing the bill and getting on board with leadership. And in the meantime, according to the source who spoke with the senator, he’s getting used to having more Senate clout than ever before.

“I think he’s having a lot of fun with it,” he said.