The measure lays the groundwork for legislation later this year that over a decade would pour mountains of federal resources into their top priorities. Included would be more money for health care, education, family services and environmental programs and tax breaks for families, with much of it paid for with tax increases on the rich and corporations.

The budget’s introduction marks the start of a long legislative trek through Congress of legislation that Democrats hope will result this fall in a progressive reshaping of government. To succeed, they’ll have to overcome likely unanimous Republican opposition and find the sweet spot between the demands of their own often antagonist progressive and moderate factions.

“At its core, this legislation is about restoring the middle class in the 21st Century and giving more Americans the opportunity to get there,” Senate Majority Leader Chuck Schumer, D-N.Y., said in a letter to his colleagues that unveiled the plan.

The resolution calls for creating free pre-Kindergarten for three-and four-year-olds and two years of free community college; extending tax breaks for children and some low-income workers; and establishing paid family and sick leave.

Medicare coverage would be expanded to cover dental, hearing and vision benefits. Spending would increase for housing, home health care and job training, and new resources would go to efforts encouraging a faster transition to clean energy.

To pay for the plans, taxes would be raised on wealthy people and large corporations, without any increases on people earning under $400,000 a year, a key Biden campaign pledge. The budget also calls for reducing the prices the federal government pays for pharmaceuticals it buys for Medicare recipients, a long-time goal of Democrats who want the government to be allowed to negotiate those prices.

The budget also calls for giving legal status to millions of immigrants living in the U.S. illegally, and—in a step aimed at winning support from moderate Democrats—spending money to strengthen border security.

Democrats are expected to approve the resolution over unanimous Republican opposition. Passage of the budget is crucial because it would allow a subsequent bill—actually enacting Democrats’ 10-year, $3.5 trillion plan for spending and tax changes—to pass the Senate by a simple majority.

Without that protection, the follow-up measure would fall prey to a GOP filibuster, delaying tactics that require 60 votes to end. Even so, it’s expected to take Democrats well into the fall to complete their $3.5 trillion package as rival progressives and moderates jostle over which of their priorities will survive.

Senate debate on the budget resolution will begin as soon as the chamber approves a bipartisan $1 trillion infrastructure package, which is expected soon.

In contrast to that compromise, though, Republicans are solidly against Democrats’ $3.5 trillion plan. They see the fight as a politically fertile one in the runup to next year’s elections for House and Senate control, and are planning to force votes on amendments on issues like immigration, crime and inflation that they think will play to their benefit during next year’s campaigns.

Democrats’ $3.5 trillion fiscal outline “will thrust the Senate into an ultra-partisan showdown over the staggering, reckless taxing and spending spree” they want, Senate Minority Leader Mitch McConnell, R-Ky., said last week.

With his eyes clearly on the November 2022 voting, McConnell said Schumer is making Democrats vote on “nothing less than Chairman Sanders’ dream shopping list. Every American family will know exactly where their senator stands.”

That’s a reference to progressive Sen. Bernie Sanders, I-Vermont, who chairs the Budget Committee.