Once again, Americans are being treated to a Capitol Hill cliffhanger over a government shutdown. The themes and plot twists differ each time, but this is a formulaic drama that reveals Congress’s bipartisan failure to perform its most basic task: to fund the federal government.

This battle isn’t over the 2018 budget; lawmakers haven’t gotten there yet. It’s a fight over short-term legislation to extend current funding levels and avert a government shutdown at midnight on Friday.

One could almost — but not really — feel sorry for Republicans. This is a mess President Trump created, and Republicans are tiptoeing around him trying to fashion a temporary fix that he won’t demolish with a tantrum or a tweet.

In September Mr. Trump abruptly decided he’d be ending the Deferred Action for Childhood Arrivals program, which protects hundreds of thousands of immigrants brought illegally to this nation as children from deportation. The president has lately been demanding billions of dollars for a wasteful wall along the Mexican border — you know, the one Mexico was supposed to pay for — as a price for a measure that allows these young people, known as Dreamers, to remain here.