WASHINGTON – As President Joe Biden prepares to depart on Thursday for a week of summits in Europe, the White House and congressional Democrats are scrambling to finalize a deal on their signature domestic spending package.

If they can accomplish this, House Speaker Nancy Pelosi plans to bring a companion bipartisan infrastructure bill to the House floor for a vote before the president leaves for Rome. That bill has already been passed in the Senate and if it is approved in the House, Biden could sign it into law this week.

Asked about the domestic spending deal's timing, Biden said Monday that it would be "very positive to get it done before the trip." Biden visited New Jersey on Monday to promote the infrastructure piece of his two-part plan.

In order to satisfy key moderates in the Senate, the topline cost of the spending bill is being slashed from $3.5 trillion to between $1.5 and $2 trillion. A pivotal vote, centrist Democratic Sen. Joe Manchin of West Virginia, is still insisting that its cost doesn't exceed $1.5 trillion.

To bring the overall price tag down, Democrats are making some hard choices. Several of Biden's campaign promises have been abandoned altogether, like providing free community college and instituting a clean electricity standard with penalties for utilities that don't comply. Other programs that were initially going to be permanent will instead expire in a year or two, such as the expanded Child Tax Credit and expanded Medicaid.

Still more plans were on a knife's edge Monday, such as a plan to expand Medicare to include hearing, vision and dental care coverage. This plan is popular with both voters and with members of Congress, but it's also expensive, projected to cost around $350 billion over a decade.

Over the weekend, Pelosi acknowledged that Democrats are considering whether to cleave off the most expensive of the three Medicare services, dental care, in order to cut the cost. "Dental is very expensive," she told CNN.

Another provision being reworked on Monday was paid family leave, a hallmark piece of Biden's pledge that his bill would ease the financial burden on working families.

Democrats initially wanted 12 weeks of guaranteed paid family and medical leave for every U.S. worker, a benefit that was projected to cost nearly $500 billion over a decade.

As negotiations have progressed, however, that plan has been scaled back. As of late last week, the White House was working on a plan to provide 4 weeks of paid leave to low-income workers, who are more likely to work in jobs that don't offer paid leave.

Much of the cost-cutting is being done to appease one senator, Democrat Joe Manchin of West Virginia. On Sunday, Biden hosted Manchin and Senate Majority Leader Chuck Schumer for breakfast at his house in Delaware. It's rare for presidents to host individual members of Congress for a meal, let alone one on a Sunday at the president's private residence. The meeting underscored Manchin's pivotal role in the outcome of this week's talks.

Manchin told NBC Monday he is still insisting that the bill not exceed $1.5 trillion.

As for what the negotiators might achieve this week, Manchin said he believed there would be a "conceptual framework" by the end of the week.

Whether a "conceptual framework" of social spending is enough to satisfy House progressives is a big, unanswered question.

House progressives have already blocked two scheduled votes on the bipartisan infrastructure bill by pledging to sink it unless they had a final deal on the social spending plan.

Costs aren't the only part of the bill that were still up in the air Monday, however. So was how to pay for it, especially after Arizona Sen. Kyrsten Sinema said last week that she opposed two pillars of the Democrats plan until now: An increase in the corporate tax rate to 25 or 26% and a return to the pre-Trump top individual tax rate of 35%.

Without these revenue raisers, Democrats are being forced to go farther afield in search of money to pay for their plans.

A growing number are warming up to the idea of a "billionaire's tax," a special tax on the 800 or so wealthiest Americans.

Not long ago, this kind of laser focus on taxing billionaires was embraced only by the party's far left flank.

"We probably will have a wealth tax," Pelosi said on CNN. "But, again, it's only 10% of what we need" to pay for the plan.

Other proposals include stepped up IRS enforcement that would include giving the tax agency access to records for bank accounts that receive $10,000 or more in non-wage deposits.

Also on the table is a global minimum corporate tax rate, a plan that has gained support this year among developed nations, but which is still very much in its early stages.