The GOP is at a breaking point over Donald Trump—as it should be.

Following Senator Ted Cruz’s crushing defeat in Indiana and the suspension of his campaign, Trump is the inevitable—presumptive!—GOP nominee based on delegate math. This means that the Republican Party frontrunner for President is not only a pathological liar but a conspiratorial, misogynistic, xenophobic authoritarian who flouts the rule of law and encourages violence to stifle dissent and free speech.

We’ve seen signs of a thaw among Republican elites towards the geriatric real-estate heir, and more establishment figures will embrace Trump in the days to come. New Jersey Governor Chris Christie was an early sell-out. Former Utah Governor Jon Huntsman—who boycotted the 2012 convention and specifically cited the party’s lack of inclusiveness—said on Sunday Republicans should get behind Trump for the sake of winning.

“We’ve had enough intraparty fighting,” Huntsman said. “Now it’s time to stitch together a winning coalition.” Former Speaker of the House John Boehner spoke warmly of his support for golfing buddy Donald last week at the flashpoint of a tight race, while calling Cruz the devil’s spawn. Today New Hampshire Senator Kelly Ayotte—up for re-election—reiterated that she will support Trump.

We are at this perilous stage in large part because of the failure of so-called leaders of the party over the past year to endorse candidates and wield their influence. With such a crowded initial field of 16 candidates, elected officials and prominent Republicans were like thirtysomethings in New York City swiping through Tinder—why settle down when something better is sure to come by? Boehner was too busy pushing Jeb Bush to enter the race, so out of touch was his grasp of the mood of grassroots Republicans, to put his support behind a more of-the-moment contender.

As establishment voices come out in support of Trump, there’s a clear dividing line being drawn between those who value power over principles, and those who don’t. Establishment figures are deluding themselves if they think Trump will suddenly “change” his un-presidential decorum now that he’s won the primary—if anything, Trump’s only constant is upholding the fundamental character flaws that should disqualify him from becoming the Republican nominee. Those who embrace Trump’s candidacy will own the downfall of our party just as much as will Trump himself.

It’s not just Trump’s consistent and flagrant disregard for the truth, in all forms, like Tuesday when Trump accused Cruz’s father of having ties to JFK’s assassination. There’s his pledge to challenge the First Amendment, commit war crimes and his cozy ties with Russian President Vladimir Putin. The list is endless, which is why the opportunism of figures like Christie and Huntsman and Boehner and Ayotte and the rest who will surely follow today and tomorrow and the next day is so staggering in its dereliction of leadership and protecting a party built on liberty.

Different Republican constituencies have begun cherry-picking what they like about Trump to justify backing him. This is fantastical. For examples, foreign-policy realists are embracing Trump for taking on neoconservatives within the GOP. Supporting Trump for speaking sense every other sentence would be a truly grievous mistake—though our country should be more thoughtful about where and when we go to war, we’d be replacing jingoistic neoconservatism warmongering for a Commander in Chief who has openly professed his penchant for committing torture and killing innocent civilians.

Which brings me to the essential choice Republican elites now have when it comes to Donald Trump: they can follow the example of Dwight Eisenhower, or that of the Kennedy clan, when it came to showing leadership facing down “Red Scare” torchbearer Joseph McCarthy.

The specter of McCarthy tormented Eisenhower from the earliest days of his campaign, and Eisenhower famously axing paragraphs critical of McCarthy from a speech at the behest of campaign advisors. Eisenhower reportedly regretted his political capitulation the rest of his life.

Once safely in the presidency, Eisenhower grappled with how to stop McCarthy, writing a friend: “It is a sorry mess, at times one feels almost like hanging his head in shame when he reads some of the unreasoned, vicious outburst of demagoguery that appear in our public prints.” Eisenhower navigated a tightrope of giving McCarthy no public attention while working against him in private by assembling the team of political foot soldiers who would ultimately take him down.

The Kennedys were among McCarthy’s strongest supporters. From his perch in the Senate, JFK protested McCarthy’s censure, writing: “His career offers an easy mark to those who wish to destroy the prestige and power of the United States.” John F. Kennedy’s father assiduously courted McCarthy, a prominent Catholic, and donated generously to his campaigns. After McCarthy’s censure, Bobby Kennedy, who had worked for McCarthy, complained, “Joe’s methods may be a little rough, but after all, his goal was to expose Communists in government—a worthy goal. So why are you reporters so critical of his methods?”

The methods towards a worthy goal, history shows us, can be as destructive as the menace. Which path does the Republican Party want to go down: that of statesmen, or one of a tyrant?

When I think back on the last 15 years since 9/11, the idea that we would throw away such sacrifice to Donald Trump makes me not just sad, but incredibly angry. The staggering loss of blood in Iraq was tragic—but to hand over our Republic to a tyrant would be far worse.

There’s plenty for elites to be ashamed of—notably, our big government foreign policy, myopic focus on tax cuts for the donor class, and the failure to address growing inequality of opportunity in this country. Let’s not add Donald Trump to that list of mistakes.

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