WASHINGTON (AP) Like Hercules and his 12 labors, Democrats $1.85 trillion package of social and climate initiatives seems afflicted by a maddening parade of hurdles. Looming ahead is the Congressional Budget Office, which could cause problems that would be messy but probably surmountable.

The office, created in 1974 as Congress nonpartisan fiscal scorekeeper, is working on a 10-year cost estimate of the bill and its component spending and tax proposals. The key question politically is how close the measure comes to paying for itself with savings, like President Joe Biden and top Democrats claim it does.

Heres a guide to understanding the numbers blizzard that CBO is about to unleash:

A BIG DEAL FOR MODERATES

After months of backbiting and bargaining among Democrats, House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer are confronting the same stubborn problem. Facing unbroken Republican opposition, Democrats can lose no votes in the Senate and just three in the House to pass their mammoth bill.

That gives Sen. Joe Manchin, D-W.Va., and his moderate House counterparts significant leverage. Among other things, the centrists want the measures savings chiefly tax increases on wealthy people, big corporations and companies doing business abroad to fully pay for its family services, health care and environment programs.