(CNN) Mitch McConnell's life is about to get a lot more complicated.

As soon as Friday, the Democratic-controlled House will vote on a privileged resolution to terminate President Donald Trump's invocation of the National Emergencies Act to secure funding to build a wall on the country's southern border. Speaker Nancy Pelosi (Calif.) has penned a letter urging all members of Congress to vote for the resolution and, given the Democratic majority in the chamber, it seems certain to pass.

Which means that it will be sent to the Senate. Where it will be required by law to be voted on within 18 days. Which could well be the longest 18 days of the Senate Majority Leader's political life.

As CNN's Michael Warren wrote way back on February 12 when considering the political impact of Trump declaring a national emergency on the wall:

"Doing so could set off a chain of events on Capitol Hill that risks splitting the Republican conference, undercutting other parts of Trump's agenda and likely opening the administration's actions to legal challenges. It may also provide a clarifying moment that Republicans on the Hill have managed to avoid since Trump took office -- casting an up or down vote on whether to build the full-scale wall Trump desires."

Uh, yeah. And every sign points to this nightmare scenario for McConnell happening -- and happening soon.

On Thursday, Senate Minority Leader Chuck Schumer made clear that if the House passes the privileged resolution, he will ensure the Senate votes on it.

"This issue transcends partisan politics, and I urge all senators -- Democrats and Republicans -- to support this resolution to terminate the president's emergency declaration when it comes up for a vote in the Senate," said Schumer. "Identical companion legislation to the House resolution will soon be introduced in the Senate."

Which is a problem for McConnell because of, well, math.

There are 47 Democrats in the Senate. The likelihood is that the vast majority -- if not all -- will vote for the resolution. (Potential "no" votes would include Joe Manchin of West Virginia and Doug Jones of Alabama.) Which means that even a half-dozen Republican defections would force the resolution to Trump's desk. (He would, of course, veto it. But it would be a major embarrassment for Trump, regardless.)

Already Maine Sen. Susan Collins has made clear she will support the resolution -- assuming nothing else is attached to it. "If it's a 'clean' disapproval resolution, I will support it," she told reporters on Capitol Hill Wednesday. She's the first Republican senator to publicly support the resolution but, in advance of Trump declaring the national emergency, there were plenty of GOP senators who expressed their concerns about such a move.

"What if somebody else thinks that climate change is a national emergency, then what will they do and how far will they go?" South Dakota Sen. Mike Rounds (R) asked in an interview with CNN on February 14. Sen. John Thune (S.D.), the third ranking GOP leader, said last month of the national emergency declaration: "Frankly I'm not crazy about going down that path. Inevitably, I suspect it probably gets challenged in court." Senate Majority Whip John Cornyn (Texas) said something similar, calling an emergency declaration "not a very practical solution to the problem."

Now, saying you don't think Trump should declare a national emergency isn't the same thing as openly breaking with the President on something he made a top priority in the campaign. And to break with him to no real end. Trump will veto it -- and there isn't two-thirds in the Senate and/or the House to overturn that veto.

After all, McConnell himself repeatedly made clear his opposition to Trump declaring a national emergency.

"I hope he doesn't go down that path," McConnell told The New York Times Magazine last month. On January 29, McConnell was even more blunt: "I am for whatever works -- which means avoiding a shutdown, and avoiding the President feeling he should declare a national emergency."

The question before McConnell and his Senate Republican colleagues is whether casting a symbolic vote aimed at sending a message that the legislative branch will not be bullied by the executive branch is worth crossing this President. (The Constitution lays out that the legislative branch is solely charged with appropriating federal funds.)

My guess is that the answer to that question is "no." But McConnell will be on pins and needles between now and when he secures that 50th "no" vote. *If* he secures that 50th "no" vote.