National emergency vote: Senate Republicans on track to rebuke Trump on marquee campaign issue

It's not a question of if enough Republicans will support a Democratic resolution to terminate the President's national emergency declaration to build a wall along the US border with Mexico. It's a question of how many.

Bottom line: The last-ditch effort to find a way to assuage concerns of Senate Republicans fell apart Wednesday, and the resolution will pass. Trump will be forced to veto the resolution -- the first veto of his presidency.

Two resolutions in the Senate are testing GOP allegiance to Trump

The bigger picture: For the second time in two days, Republican senators will join with Democrats to support a measure the White House opposes -- first on Wednesday to end military support for Saudi Arabia in the civil war in Yemen, followed by Thursday's vote to terminate the national emergency.

There are common threads here, from views of executive branch overreach to an administration that repeatedly declined -- or couldn't -- provide the information GOP senators explicitly requested as they made up their minds on these votes.

Senior Republicans are playing down the votes as some kind of major rift -- and they aren't wrong. After all, Senate Republicans, many of whom were initially wary, are now fully behind the President on the border wall specifically, and the administration's overall border security goals.

"It's not like this signals some big break from the President going forward," a GOP senator told CNN. "But it is an example, one maybe we've avoided the last few years, that we can push back and send a message when we need to."

In tweets, Trump has continued to cast the vote as a binary choice, between his border security proposals and supporting Democrats.

Administration officials were still in discussions with senators and staff throughout the day Wednesday. But Trump himself put an end to any hope of killing the resolution when he called Republican Sen. Mike Lee during a closed-door Senate GOP lunch and made clear he wouldn't support his proposal to limit future national emergency declarations to 30 days.

Later in the day, in a meeting with GOP senators about trade, Trump went back to the resolution vote and attempted to lobby skeptical senators, according to Republican Sen. Lamar Alexander, who was there.

But Alexander made clear it was done in a way he "appreciated."

"He would like for us to vote against the amendment," Alexander said when he returned from the White House. "But he understands and respects that senators may have different opinions."

When CNN mentioned Alexander's comments to an aide with knowledge of the meeting, he said the senator's assessment tracked with what he'd been told, but noted: "We'll see how long that understanding and respect holds after senators vote against him this afternoon."

Nothing is official until Senate Majority Leader Mitch McConnell announces it on the floor (but aides in both parties say the target is in the early afternoon -- sometime after lunch).

A technical addendum on jet fumes: This will be the last vote before a week-long congressional recess. Senators won't want to prolong this process any longer than they procedurally have to.

Who to watch

As is often the case with votes like this, there are a good number of senators who have kept their powder dry on how they will vote. As one senior GOP aide explained, "there's no reason to put a target on your back while talks are still ongoing and there's still some shot of a way out."

Well, that shot is officially gone.

So, as is also the case with votes like this, expect a flood of statements and/or tweets to come out shortly before the final vote. Nothing is official until a senator gives a thumbs up or down on the floor, but here's a rough outline of who to watch, based on conversations with GOP senators and aides:

Confirmed NO votes

Sen. Susan Collins

Sen. Lisa Murkowski

Sen. Mike Lee

Sen. Rand Paul

Sen. Thom Tillis* (note: Tillis has been somewhat circumspect about his vote in the last few days as he's worked on a compromise with the administration)

Likely NO votes

Sen. Lamar Alexander

Sen. Mitt Romney

Possible NO votes

Sen. Ted Cruz

Sen. Pat Toomey

Sen. Jerry Moran

Keep an eye on

Sen. Roy Blunt

Sen. Rob Portman

Sen. Ben Sasse

Sen. Roger Wicker