Mainstream Democratic lawmakers are seething about the fact that centrists in their party have the final say on what will be included in the Build Back Better budget reconciliation bill. It’s just math, though. If you need Kyrsten Sinema and Joe Manchin’s votes, you have to produce something they find acceptable.

I’ve argued that it’s not a great idea to constantly insult them since they’re in total control, but a lot of Democrats can’t help themselves. It’s easy to see why when we begin to consider what it will take to reduce the BBB’s price tag from $3.5 trillion down to $1.5 trillion. Jeff Stein of the Washington Post, explains that just “funding climate change, creating a national paid leave program, and extending a tax benefit that alleviates child poverty” would leave no money left over for anything else the Democrats promised during the 2020 campaign.

Democrats’ health care goals alone could cost in the range of $750 billion if extended over the next decade. House Speaker Nancy Pelosi (D-Calif.) wants to spend hundreds of billions of dollars on new Obamacare subsidies, while Senate Budget Committee Chairman Bernie Sanders (I-Vt.) wants to spend hundreds of billions of dollars to add dental, vision and hearing benefits to Medicare. Other Democrats, such as Sen. Raphael G. Warnock (D-Ga.), are pushing to expand Medicaid eligibility to poor Americans in Republican-run states that so far have refused to take advantage of extra Medicaid dollars made available under Obamacare.

There are ways to play around with the numbers to fit more priorities into the bill, but this mainly involves allowing programs to sunset after a certain number of years, limiting who can access or benefit from programs, or funding them at such inadequate levels that they may not be effective.

There’s an argument for doing just a few things very well, especially if millions of people will notice. There’s also an argument for keeping as many promises as possible and seeing what sticks. Either way, it’s painful and politically perilous.

I learned a long time ago that part of being in a broad political coalition is accepting that you can’t go around telling people that their top priorities are less unimportant or will have to wait. That’s why I’m not going to argue that this or that priority should be cut from the bill. But I do think that advocates for certain policies, whether it be access to health care, childhood hunger, or something else, should focus on the virtues of their programs rather than on who donates money to Sinema and Manchin. They get to decide if a little more money can be included for your priority or not, and it’s human nature not to reward critics who insult your integrity.

However arbitrary it may be, Sen. Manchin insists he isn’t spending a penny over $1.5 trillion. Biden and Pelosi are hoping he’ll come up a little from that number to something more like $2.1 or $2.3 trillion. If he agrees, it could cover most of their health care goals. Maybe the best strategy is to tell Manchin that West Virginians’ teeth are on the line. I mean, he can explain that kind of expenditure very easily.

This is an unpleasant situation. It’s a bit like a bunch of grandchildren jockeying to get more of their mean old grandmother’s inheritance. They may cringe at the things she says, but they humor her anyway because she has something they want. Everyone feels dirty in these scenarios, but someone winds up winning. Whether it was worth it depends on the details.

Of course, grandma can decide she doesn’t like any of the grandchildren and leave her inheritance to the Republican Party. In that case, everyone can agree that she was a nasty old crow, but that won’t feed a child or get someone a dental appointment.