In a stunning and embarrassing rebuke, 12 Senate Republicans voted for a resolution to overturn President Donald Trump’s national emergency border wall declaration on Thursday.

By choosing to defy a Republican president, these Republicans have stood up for the separation of powers, the rule of law, and the constitution—and against executive overreach. It was the rare instance of Congress showing itself to be both strong and willing to stand for itself against the executive branch. Though the numbers are not there to override a veto of the measure that Trump has already said he’d issue, Thursday nevertheless marked an important moment in our current politics. Let’s hope it is a sign of things to come.

I’ve been willing to criticize Republicans in the past, so it’s only fair to give credit where it’s due. Having drawn a red line on this defining vote, these Republicans deserve our praise and respect.

This was a gutsy move. They bucked their party’s standard bearer on his signature issue. They did the right thing when it counted. And there will very likely be retribution from the president, who not only viewed this vote as a loyalty test but is certainly aware that there will be more breaks in the dam down the road if he doesn’t inflict payback in the present.

“ A vote for today’s resolution by Republican Senators is a vote for Nancy Pelosi, Crime, and the Open Border Democrats!” declared Trump on Thursday morning.

It was one of several warning shots fired by the president and his enablers in the run-up to the vote.

On Wednesday, Fox Business host Lou Dobbs told RNC Chair Ronna McDaniel that “every senator who votes against this should absolutely be removed from office” and that “the RNC should work to get rid of them because they’re standing in the way of a president who is the most successful in the first two years of his presidency since FDR.”

Think about that. What Dobbs proposed would require McDaniel to help oust her own uncle Mitt Romney from office.

Or consider the case of North Carolina Senator Thom Tillis. Tillis was an early supporter of the resolution. He even penned an op-ed declaring, “As a U.S. senator, I cannot justify providing the executive with more ways to bypass Congress. As a conservative, I cannot endorse a precedent that I know future left-wing presidents will exploit to advance radical policies that will erode economic and individual freedoms.” On Wednesday, The Hill reported that “ Some county GOP party leaders are openly calling for Tillis to face a primary challenge.” On Thursday—just before the vote—Tillis suddenly flipped to support the president. I wonder why?

Overt threats aside, a lot of rank-and-file Republicans do believe the job of a Republican senator is to go along with a Republican president—especially when it comes to building a (promised) border wall.

For them, esoteric talk about checks and balances, dangerous precedents, or the constitutionality of usurping the legislative branch’s “power of the purse” authority is tantamount to dorm-room talk and niceties.

The threats worked on some senators. Some of them had better reasons than others. Just before the vote, Louisiana Senator Bill Cassidy was on CNN making the argument that (a) Congress should have previously imposed guardrails to prevent a president from doing what Trump is doing, but (b) since Congress, instead, ceded authority to the president, that Cassidy would (c) vote to support Trump’s emergency order. Pretty weak sauce, if you ask me.

Other Republicans—like Ted Cruz and Ben Sasse—voted with Trump for other, somewhat inexplicable, reasons.

Never Trumper Bill Kristol has been tweeting a 2014 video of Ted Cruz passionately arguing that "it's incumbent on Republicans in Congress to use every single tool we have to defend the rule of law, to rein in the president, so that the president does not become an unaccountable monarch.” That was Cruz’s stance on executive overreach when Barack Obama was president. This is obviously hypocritical.

In the case of Sasse, voting with Trump is shockingly off-brand. But, like Tillis, he’s up for re-election in 2020. And as I have previously observed, one of the problems with Trump is that he puts Republicans in the untenable position of having to choose between having relevance and influence or having dignity and integrity. Tillis, Cory Gardner, Sasse and others chose the former, at the expense of the latter. I hope they sleep well.

But far more Republicans than I would have imagined rose to the occasion and did the right thing. It’s also arguably an even nobler vote when you realize that after President Trump vetoes the bill there likely won’t be enough votes to override that veto.

Still, symbolic victories matter, and this could demonstrate to Republicans that they can, in fact, stand up to this president—that the sky won’t fall. If nothing else, this gives us hope in the future, and allows us to respect 12 senators (and 13 House Republicans).

Also, someday soon (and it may be sooner than we think) a Democratic president will attempt to use Trump’s emergency declaration as a precedent to unilaterally act on some item they see as an “emergency.” When that happens, Cruz will undoubtedly contort himself once again. But for those who cast a principled vote today, it will be easy to oppose the measure.

I do have one word of advice for the 12 Republicans who voted in favor of this resolution: Don’t back down and switch votes when the (likely doomed) time comes to override the veto. If you do that, not only will you fail to appease the most vehement Trump loyalists who will still question your commitment to Trump, but you will also undermine and alienate those of us cheering you on today.

Even if you can’t override the veto, don’t back down from this principled stand. We’re counting on you to maintain a foothold for constitutional conservatism.

You did the right thing, today. Don’t fold now.