As the first woman to clinch a major party nomination, Hillary Clinton’s candidacy is already historic – and increasingly it looks like Donald Trump’s is too. But not in a flattering way.

If last week came the point at which he self-immolated the campaign and beloved Trump brand, this week may be remembered as the time he finally drove his party’s national security leadership to support the Democratic candidate for president en masse, either by voting for her expressly or by abstaining.

National security is an issue that Republican presidential candidates have historically been able to dominate, but Trump may be the first guy in recent history to blow that for the party. Even more remarkable is that top neoconservatives in the party are all taking the Democrat’s side: Clinton has said Trump “shouldn’t have his finger on the button” of our nuclear arsenal. It looks like even Republican top brass agrees.

On Thursday a long list of GOP national security hands wrote a letter saying Trump would be “the most reckless president in American history” and that electing him in November would put the nation’s security at risk. Some of the 50 signatories said they’d vote for Clinton while others deemed it better to abstain from voting entirely. But all were in fundamental agreement on one main point: “Trump is not qualified and would be dangerous.”

This comes after Evan McMullin, a former CIA official who recently worked for the House Republican conference, filed papers to run for president as an independent candidate. He doesn’t support Clinton, and having missed the ballot-access deadlines in most states, the move is expected to have little effect on the race other than to help the former secretary of state by cutting into Trump’s margins. But that’s just fine with McMullin, who says: “It’s never too late to do the right thing.”

In fact if there’s a common theme to this most recent wave of GOP dissenters, it’s just how eerily close they sound to Hillary Clinton’s talking points.

“He is unable or unwilling to separate truth from falsehood,” the GOP national security leaders said in the letter. “He does not encourage conflicting views. He lacks self-control and acts impetuously. He cannot tolerate personal criticism. He has alarmed our closest allies with his erratic behavior. All of these are dangerous qualities in an individual who aspires to be president and commander in chief, with command of the US nuclear arsenal.”

Some in recent interviews have specifically cited Trump’s recent comment inviting Russia to hack into Clinton’s email servers, a remark Trump has since claimed he was making in jest, as the moment that changed their mind about him. They also touched on his embrace of Putin specifically, calling his admiration for him and other foreign dictators “unacceptable”.

That sounds a whole lot like what Clinton’s been saying all along, if not what Barack Obama said at the Democratic convention last month when he called Trump’s rival the most qualified presidential candidate in history.

In our era of political polarization and congressional stagnation, it’s been ages since top Republicans and Democrats in Washington could agree on anything more definitively than the need to keep Trump out of the White House. And without getting ahead of ourselves too much (for Trump’s done nothing this election so well as outperform low expectations), let’s hope the unlikely unity extends beyond the neocons and with any luck, lasts longer than the election.