CNN  — 

Missouri Sen. Roy Blunt’s surprise retirement announcement Monday adds his name to a growing list of GOP establishment politicians who no longer recognize the party they represent and have decided to walk away rather than face the peril of losing their career at the hands of a Donald Trump-inspired base that views them a insufficiently loyal to the cause.

To date, five Republicans senators – Blunt, Richard Shelby (Alabama), Richard Burr (North Carolina), Pat Toomey (Pennsylvania) and Rob Portman (Ohio) – have all announced that they will not seek another term next November. It’s not a coincidence that all five are considered remnants of the Republican Party of George W. Bush and have struggled to adjust to the new Trump-led GOP.

“The rash of GOP retirements, likely to avoid Trump madness in the primaries, shows you Trump still isn’t done destroying the party,” tweeted conservative commentator (and CNN contributor) Amanda Carpenter after Blunt’s retirement announcement. “Onwards we go.”

The trend is hard to dispute.

Blunt, prior to Monday morning, was not seen as someone even considering not running again. He had spent a lifetime in politics – including a stint in House leadership – and is a close ally of Republican Senate Leader Mitch McConnell (Kentucky). And with the Republican trend in Missouri, Blunt’s path in a general election in 2020 is probably clearer than in either of his past two Senate bids.

But Blunt isn’t a Trumper. In the wake of the January 6 US Capitol riot, Blunt said that Trump had been “clearly reckless” although he insisted, wrongly in retrospect, that “the President touched the hot stove on Wednesday and is unlikely to touch it again.”

Temperamentally, Blunt prefers to work behind the scenes – the polar opposite of Trump. George W. Bush once referred to Blunt as a “leader who knows how to raise his sights and lower his voice,” which is, quite literally, the opposite of Trump’s leadership, uh, “philosophy.”

What all that meant is that Blunt faced at least the possibility of being primaried by a Trump-ier candidate next year. And given that Missouri’s other senator is Josh Hawley – he of the push to question the Electoral College counts in several states (Blunt voted against those objections) – there’s plenty of reason for Blunt to be slightly nervous as he looked toward where he fits in the current version of the party.

“A vote of no confidence in the Senate - and the easiest way of sidestepping Trump loyalty tests in next year’s primary,” tweeted The New York Times’ Jonathan Martin about the Blunt retirement.

Ditto Portman who needed to look only as far as the chatter surrounding a potential Trump-ier challenge to Gov. Mike DeWine (R) in 2022 to see what might have awaited him in a year’s time. In his retirement announcement, Portman hinted at the frustrations born of being in a party where compromise is a bad word. “I don’t think any Senate office has been more successful in getting things done, but honestly, it has gotten harder and harder to break through the partisan gridlock and make progress on substantive policy, and that has contributed to my decision,” he said.

Same goes for Burr. And Shelby, And even Toomey, who, although he was elected as a conservative firebrand, showed a willingness to work across the aisle – most notably on unsuccessful gun reform legislation with West Virginia Democratic Sen. Joe Manchin.

“Congress is no place for a sensible Republican anymore,” tweeted Brendan Buck, a former top aide to speakers John Boehner and Paul Ryan, following Portman’s retirement announcement. Buck was right then. He’s even more right following Blunt’s no-go decision.

The fleeing of the establishment has dovetailed with the rise of the Trump wing of the party – even in the Senate, which has always prided itself on being less reactive to the short-term changes within the party.

Witness the aforementioned votes on objections to the Electoral College results. Seven senators voted for the objection to the Pennsylvania results despite the fact there is no objective evidence of allegations of fraud or stealing of the election. Of those seven, six (Hawley, as well as Mississippi’s Cindy Hyde-Smith, Wyoming’s Cynthia Lummis, Kansas’ Roger Marshall, Alabama’s Tommy Tuberville and Florida’s Rick Scott) were elected or appointed between 2018 and 2020. (The lone exception was Texas Sen. Ted Cruz, who was elected in 2012 but badly wants to run for president in 2024.)

Given the clear signals of where the GOP is – and where its heading – its uniquely possible that more retirements among Republican establishment Senators will come. Iowa Sen. Chuck Grassley, who has served in the body since 1980, has said he will not make a decision about running for an eighth term until the fall. There’s also the question of Alaska Sen. Lisa Murkowski (R) who appears to be the top target of the former President.

“I will not be endorsing, under any circumstances, the failed candidate from the great State of Alaska, Lisa Murkowski,” Trump told Politico in a statement on Sunday. “She represents her state badly and her country even worse. I do not know where other people will be next year, but I know where I will be – in Alaska campaigning against a disloyal and very bad senator.”

While pundits like to debate over who really controls the Republican Party now, the actions of the likes of Blunt and Portman say it all: This is Donald Trump’s Republican Party. And the past GOP establishment isn’t really welcome.