One way to measure just how much Congress has changed is to look at the legislative circumstances during the last impeachment.

In December 1998, as the House impeached President Bill Clinton, it had Washington to itself. The Senate was gone, long gone, in fact, with that chamber’s last roll-call vote occurring almost two months before the House’s Dec. 19, 1998, impeachment votes.

That era’s Congress finished its annual work by mid-October, before the midterm elections, and the only business of the lame-duck session was debating a presidential impeachment. With the constitutional clash on a stage by itself, the debate carried an extra sense of gravity as the only order of business on Capitol Hill.

Flash forward 21 years, and it’s a completely different scene during the impeachment of President Trump. Over the next 12 days or so, the House and Senate expect to reel off a litany of last-minute legislating that will attempt to make up for months of institutional inaction.

The other initiatives will include everything from the predictably overdue items that must pass every year — funding bills for federal agencies and Pentagon policy — to the more sweeping plans to create a new Space Force and approve the most important trade deal in at least two decades.

Time is so short, as lawmakers set a tentative goal of exiting town Dec. 20, that leaders now only expect a day of formal debate on the House floor for the United States-Canada-Mexico Agreement.

“Yes, it may not be a long debate on the floor, but it’s been a very long debate, a very hard negotiated conclusion,” House Majority Leader Steny H. Hoyer (D-Md.) told reporters Tuesday.

The same timeline is likely for impeachment, one day of formal debate and then votes.

“I think it will be the culmination of a long, long discussion and debate and hearings, intense work over the last two months, intense work over the last two months,” Hoyer said, repeating himself for emphasis.

Hoyer, whose job description includes scheduling the House floor, is trying to thread a needle that can allow for many of those bills to then head over to the Senate, where cumbersome debate rules will require an extra few days to process legislation.

By some measure, impeachment — likely to come late next week — is one of the easier lifts because it is expected to break predictably along party lines against Trump, although the GOP majority in the Senate is in strong position to acquit him in a trial beginning early next year.

The pileup of leftover issues is so large that some matters were deemed too difficult to handle before the Christmas break.

Senate Majority Leader Mitch McConnell (R-Ky.) announced Tuesday that the impeachment trial — which technically would start just after the House approves a single article — will wait until early January to kick off.

McConnell also said Senate votes to approve the trade agreement, which might be the House’s last vote of the year, just after the partisan impeachment vote, must wait until the Senate trial concludes.

Like college students cramming for finals, congressional leaders first must approve the dozen annual funding bills for federal agencies or else face another government shutdown over the holidays.

“What we must do is pass an appropriations bill, that’s what we must pass, to keep government open. So that’s the first order of business,” House Speaker Nancy Pelosi (D-Calif.) told reporters Monday evening.

Those bills are already two-and-a-half months overdue, and they really are not a dozen separate bills anymore. A couple of years ago congressional leaders gave up any effort to do what was once considered basic work, passing each bill individually, and instead cobble them together into a couple of large bills, colloquially known as “minibuses,” with each one funding about half the federal government.

Pelosi and McConnell, who grew up in the House and Senate Appropriations committees, play a particularly hands-on role on this work, all of which is complicated by Trump’s demands for border wall funding that lacks sufficient congressional support and prompted a 35-day partial shutdown over the holidays last year.

The next 48 hours will determine whether there is a deal to drive those spending bills through the House, which would happen Tuesday or Wednesday of next week followed by a tricky set of moves to win Senate approval by the Friday deadline.

“If we have total agreement, we have enough time,” said Sen. Patrick J. Leahy (Vt.), the top Democrat on the Senate Appropriations Committee.

In a scene resembling a Hollywood movie, Leahy said that he used Sunday evening’s Kennedy Center Honors to huddle with Hoyer and Sen. Richard C. Shelby (R-Ala.), chairman of the Appropriations Committee, to continue the talks.

Shelby and Leahy had breakfast Tuesday with Defense Secretary Mark T. Esper, whose annual budget gets the largest chunk of an overall $50 billion increase in agency funds under the summertime framework deal.

First Congress will attempt to pass the Pentagon policy bill, likely for Thursday in the House and early next week in the Senate.

It was held captive for months by somewhat unrelated matters, because everyone knows it is a must-pass bill, and it is serving as a legislative Christmas tree this year — liberals getting a new law providing expanded federal worker leave and Trump getting the creation of his Space Force.

All this had already built a massive backlog of issues to process, and then came Tuesday’s trade announcement.

“We’ve been saying for months that we can legislate and investigate at the same time, that we can walk and chew gum. Right? We’ve been saying for months that we can do that, and here we’re doing it,” said Rep. Jim Himes (D-Conn.), a senior member of the House Intelligence Committee that investigated Trump’s actions with Ukraine that led to the impeachment articles.

So, with the trade deal getting such broad support, Pelosi is likely to place that as the last vote of the year, possibly Dec. 20.

That would put the impeachment vote just before then, which means the House would vote a day or two before on impeachment, quite possibly on Dec. 19 — the exact anniversary when the House last voted to impeach a president.

But that is about the only thing that might be the same.