In order to fit $3.5 trillion worth of spending into a $2 trillion box, progressives recommend immediately implementing all of these programs but “sunsetting” them—allowing them to expire—after a shorter number of years, so they appear to cost less over ten years. It is not that progressives actually want these programs to expire, though. Instead, they’re resorting to the use of “cliffs” as, essentially, a budget gimmick.

The idea is that once popular benefits have been introduced, it would be difficult for the governing party to allow them to disappear overnight. They would be renewed in some form or fashion. This is a bipartisan trick: The George W. Bush tax cuts were designed to sunset after ten years, and were mostly renewed—except at the top end—under Barack Obama. The Republican tax cut bill in 2017, meanwhile, scheduled all of the individual tax cuts to expire at the end of 2025. That way, Republicans had enough budget space to make all of their business tax cuts permanent, and pretty good historical precedent to believe that most of the individual tax cuts would be renewed later on.

One issue with setting up “cliffs” is that Manchin and Arizona Sen. Kyrsten Sinema, and other conservative Democrats, are wise to the idea that this is a budget gimmick disguising the true cost of programs, and won’t want to go along with it. But it’s also an enormous risk to enact so much of your vision for a new social contract on a few-years’ basis and bet that Republicans, likely to return to power in at least one chamber of Congress, wouldn’t allow many of these programs that they hate to expire. Have you met a House Republican? Have you heard Mitch McConnell speak words before?