The thing is, they don't even need to pass it for their plan to backfire. FDR tried to pull those shenanigans when parts of the New Deal got struck down, and even though he didn't succeed in packing the courts, the following elections drastically swung Congress back towards the Republican Party. They didn't claim a majority, but they were no longer the party-in-exile they had been since the Great Depression kicked off.
Right now, the Dems have the slimmest of majorities in the House, and an even split in the Senate. Assuming they don't get up to even more electoral fraud shenanigans, pulling shit like this could easily flip both chambers back to red. And that's before getting into any other potential failings that may play out over the next two years, the biggest being a botched coof response and a downturn in the economy. And let's not forget the radical left that keep running their mouths about how we can totally pass a ten trillion dollar bill or how we need to abolish the police and military. That shit's guaranteed to turn off a lot of people.