This post has been updated with the latest news.
With a March 5 deadline looming for dreamer deportations, Pelosi launched an extremely rare filibuster, something that hasn't happened with in more than a century and technically isn't even allowed in the House, said congressional rules expert Joshua Huder.
Besides being procedurally noteworthy, Pelosi's filibuster means that the chances for a second government shutdown in as many months just went up, although by how much is to-be-determined.
A long-term spending deal that the Senate is closing in on needed Democratic help to pass the House
Both sides of Congress are like ships passing in the night, doing their own thing on the budget. The House on Tuesday passed its own short-term spending bill, largely without Democrats' help.
The Senate was plowing ahead with its budget deal, which proposes billions more in domestic and military spending and does not protect dreamers, foreign-born people who were brought to the United States illegally as children or who overstayed their visas as children. That's a non-starter for House conservatives, who don't want to raise spending levels by that much on nondefense spending.
The Senate was hoping at least House Democrats would get on board their ship and vote for their version of a spending deal to help it pass the House.
Now, that plan might be wrecked if Pelosi holds to her word, joined by enough House Democrats, that they won't vote for a spending bill without a vote on dreamer protections. It's not clear how many Democrats are with Pelosi.
“If she speaks for the entire Democratic caucus, then Trump will get his shutdown,” said Steve Bell, a former Senate GOP budget aide now with the Bipartisan Policy Institute.
Pelosi's demands set her up for a direct confrontation with Trump over immigration
As Bell alluded to, Trump seems totally fine with a government shutdown. Less than 24 hours before Pelosi's filibuster, he said: “I’d love to see a shutdown if we don’t get this stuff taken care of” — “this stuff” meaning immigration.
In some senses, Trump and Pelosi both want the same thing: They want changes to immigration badly enough to risk a government shutdown. But they also want very different changes to immigration.
Trump wants Congress to support his proposal that drastically limits legal immigration (going further than most mainstream Republicans want to go) in exchange for providing a path to citizenship for about 1.8 million dreamers.
Pelosi wants nothing to do with the legal immigration changes. She's singularly focused on protecting dreamers after taking heat from activists and the left wing of her party for letting Congress tip right up to the dreamer deadline without a deal.
So even if she did get a vote on dreamers, and even if it did pass the Senate, too, there is no guarantee Trump would sign it. Especially since any deal Pelosi likes would probably have no sizable chunk of money for Trump's border wall, said nonpartisan budget expert Stan Collender.
It's also worth pointing out that the last time the government tried tying immigration to spending bills, the government shut down. Democrats in the Senate agreed to reopen it a few days later, without any concrete deal on immigration except a loose promise to vote on protecting dreamers.
Indeed, the lead-up to the shutdown concentrated in the Senate is eerily similar to what's happening in the House now: A significant chunk of one party refusing to vote for a spending bill unless Republican leadership agrees to demands that it may not be able to agree to.
Which brings us to our third and final point on why the chances for a shutdown just escalated:
This sets Pelosi up on a collision course with Ryan
Pelosi has long maintained that if a bill to protect dreamers were put on the floor, it would pass the House.
But there's a reason the House hasn't voted on protecting dreamers yet. There may be a majority in the House that wants to protect dreamers, but Ryan may not have the support of a majority of House Republicans to do this. And when Ryan became speaker, he promised his party in the House that he wouldn't bring up a bill for a vote (even though he has the power to as speaker) unless a majority of his party supports it.
Ryan spokeswoman AshLee Strong told my Washington Post colleagues that Ryan has said he does intend to vote on a deal protecting dreamers, but there's a catch. It has to be “one that the president supports.” (See above for why that's going to be difficult.)
Now, we could be entering a classic shutdown showdown: Both sides have staked out their positions, and unless one relents or a deal is cut soon, a shutdown is entirely possible.