When Adam Kinzinger launched his career in Republican politics in 2010, the Illinois congressional candidate welcomed the support of Sarah Palin and Tea Party groups. It was widely assumed that the young military veteran — Kinzinger was only 33 when he first arrived on Capitol Hill — would be a reliable ally of the GOP’s conservative base.

And on most substantive issues, those assumptions proved true. Kinzinger was often described as a relative moderate in his party, but his voting record reflected the congressman’s conservative worldview. While no one ever lumped him in with the GOP’s partisan bomb-throwers, Kinzinger rarely broke party ranks.

But voting records only tell part of a larger story. While casting conservative votes on many key issues, the Illinois congressman saw his party drifting further away from democratic principles and aligning itself with Donald Trump. Kinzinger seemed determined to resist the tide and help prevent his party from drifting further into madness.

That is, until this morning, when the Republican lawmaker announced he won’t seek re-election. NBC News reported:

The 43-year-old Illinois representative announced his decision to retire from Congress in a five-minute-long video posted on social media. He said that during his first campaign for Congress more than a decade ago, he told himself “that if I ever thought it was time to move on from Congress, I would, and that time is now.”

It’s far from clear what Kinzinger’s next move might be. In the spring, he told the Chicago Sun-Times that if Illinois’ Democratic legislature drew an unfriendly district map, it would make a U.S. Senate or gubernatorial race “a little more attractive, I guess.”

It was against this backdrop that the congressman’s video added this morning, “This isn’t the end of my political future — but the beginning.”

With this in mind, it’s understandable that some of today’s coverage is focusing on gerrymandering. After all, Democratic legislators in Illinois — just like Republican legislators in several red states — sliced up the state’s congressional districts to maximize partisan goals. As such, if Kinzinger ran for another U.S. House term next year, he’d likely have to run against a fellow incumbent Republican, Rep. Darin LaHood, in a primary.

Given Kinzinger’s weak support with the GOP base, that’s a primary he’d likely lose.

But let’s not miss the forest for the trees. In recent years, Kinzinger’s career has been defined by his efforts to rescue the Republican Party from its radical trajectory. His goals were less about specific policy measures and more about democracy itself — and the GOP’s hostility towards democracy’s principles.

After the Jan. 6 attack on the Capitol, for example, House Democratic leaders pushed a resolution calling on then-Vice President Mike Pence and the White House cabinet to remove Trump from office. Kinzinger was literally the only GOP member to vote for it.

Soon after, 10 House Republicans voted to hold Trump accountable through impeachment, and Kinzinger was one of the 10. He proceeded to plead with Senate Republicans to convict Trump, insisting it would help “save America from going further down a sad, dangerous road.” (Most GOP senators ignored the advice.)

Recommended

Maddowblog

Nearly five years later, the ranks of the GOP’s Impeachment 10 are nearly gone

Steve Benen

Maddowblog

Why the scheduled military funeral for Jan. 6 rioter Ashli Babbitt is indefensible

Steve Benen

A few weeks later, Kinzinger told The Atlantic, “I think we will start to see by the summer where we’re at. If 20 percent of the Republican base is ready to move on from Trump today, and it’s 25 or 30 in the summer, that’s a good trend. If in the summer it’s 18 or 20 percent, that’s a bad trend. I think summer’s check No. 1, and then, obviously, the 2022 election is check No. 2. But if that 20 percent grows to 35, 40, 45 percent, this party might be salvageable.”

In the months that followed, House GOP leaders effectively stopped talking to Kinzinger, especially after he voluntarily agreed to serve on the bipartisan select committee investigating the Jan. 6 attack.

And now that Kinzinger is giving up his House seat, it suggests he’s not pleased with his progress in “salvaging” the Republican Party.

Last month, Republican Rep. Anthony Gonzales of Ohio, another one of the 10 House GOP members to vote for Trump’s second impeachment, announced his retirement, adding that the former president is “a cancer for the country.” Gonzales’ decision served as a reminder: This is Trump’s party now, and dissenters will be purged.

Kinzinger’s decision appears to be part of the same trend.

After Gonzales’ announcement, the former president taunted his intra-party foes, saying in a written statement, “1 down, 9 to go.” It’s a safe bet that Trump will respond to Kinzinger’s news the same way.