On Thursday night, Charlie Dent, a Republican who's been representing Pennsylvania's 15th District in Congress since 2005, announced he will not be running for reelection in 2018. Politicians decide to leave office for many reasons, some of them private, but Dent—who's been in DC a long time and is known as a pragmatist—offered a reason for quitting that's worth pausing on. In his statement, he cited his accomplishments and record, but also delivered a rebuke to his own party on the way out the door:

As a member of the governing wing of the Republican Party, I've worked to instill stability, certainty, and predictability in Washington. I've fought to fulfill the basic functions of Government, like keeping the lights on and preventing default.

Regrettably, that has not been easy given the disruptive outside influences that profit from increased polarization and ideological rigidity that leads to dysfunction, disorder, and chaos.

Dent is a member of the Tuesday Group, a caucus of relatively moderate Republicans, and a faction that has been increasingly squeezed out of power by the loud and insurgent conservative branch of the GOP. The roots of the Republican Party's rightward lurch go back decades, but since the Tea Party surge of 2010, it's become obvious that its "governing wing" is losing power.

In 2011, conservatives nearly forced the United States to default on its debts, a bit of destructive brinksmanship that led to the US bond rating taking a hit. Not satisfied with that, two years later congressional Republicans presided over a pointless (partial) government shutdown in an attempt to force Barack Obama to scrap the Affordable Care Act (which failed, obviously). A base impatient with compromise even though Obama was in the White House led to GOP leaders like Eric Cantor and John Boehner, no shrinking violets, being forced out of power by hardline conservatives. The same hardliners also helped kill an immigration bill in 2013, ending the best attempt in years to compromise over a thorny issue currently looming over millions of people in America.

Then the 2016 primary saw Republican voters reject candidates with actual governing philosophies and experience in favor of Donald Trump, the embodiment of every simplistic urge—ideological or otherwise—in the party.

Republicans haven't proved any better at governing while in power. Most of their legislative energy this year went toward pushing through an incredibly unpopular healthcare bill that would have deprived millions of insurance, and they couldn't even get that done. (Dent voted against it as it passed the House.) Trump isn't helping them out either, feuding with Republican leaders and recently giving into Democrats' demands on the debt-ceiling debate, sending his own party into convulsions. Meanwhile, members of the far-right House Freedom Caucus are reportedly thinking about trying to dump—or at least threaten—House Speaker Paul Ryan, just like they ousted Boehner.

It's not hard to figure out what Dent meant by "increased polarization and ideological rigidity that leads to dysfunction, disorder, and chaos."

Now that Dent is out of the running in 2018, Democrat Rick Daugherty, who lost the race for Dent's seat last year, has an opening. Dent was also already facing a primary challenge from Justin Simmons, a state politician who has accused Dent of being insufficiently pro-Trump and who probably benefits the most from his resignation.

"I think right now we could say, 'Mission Accomplished,'" Simmons told Politico. "We wanted to make sure we got a more conservative candidate in the seat, and now we can do that."

And so the Republican Party takes yet another in a seemingly never-ending series of steps to the right.