WASHINGTON — Congress began 2020 the same way it wrapped up 2019: with the Senate waiting for the House to send over the articles of impeachment for President Donald Trump that the chamber passed at the end of the year — and with House leaders saying their Senate counterparts need to release more information about a possible trial on those charges before they do.

House Speaker Nancy Pelosi, D-Calif., threw Senate Majority Leader Mitch McConnell, R-Ky., a curve ball immediately after the pair of impeachment votes on charges of abuse of power and obstruction of Congress. Weeks later, McConnell and Senate Minority Leader Chuck Schumer, D-N.Y., appear roughly as deadlocked over the parameters of a trial as they did before the holiday recess.

But impeachment is far from the only big item on the congressional agenda this election year. Lawmakers, for example, are expected to receive briefings on the decision by the president last week to kill Iranian Gen. Qassem Soleimani in a U.S. strike. Here's a rundown of the latest on the Senate trial standoff, along with some of the other issues on deck to grab the spotlight:

A Senate impeachment trial

Although a Senate trial isn't certain yet, White House officials spent the final moments of the congressional session preparing for one, doing a walk-through with Senate Republican leadership.

To initiate a Senate trial, the House must deliver the articles of impeachment to the Senate and vote to name several of its members to serve as managers to prosecute the president. Neither has happened yet.

Pelosi said after the articles were adopted that she hadn't "seen anything that looks fair to us" regarding the outlines of a Senate trial. Whenever those details do emerge, she said, "hopefully it will be fairer, and when we see what that is, we will send over our managers."

McConnell said again on Friday that, in his view, the situation was the other way around.

"We can't hold the trial without the articles. The Senate's old rules don't provide for that. So, for now, we're content to continue the ordinary business of the Senate while House Democrats continue to flounder," McConnell said on the Senate floor. "But if they ever muster the courage to stand behind their slapdash work product and transmit their articles to the Senate, it will then be time for the United States Senate to fulfill our founding purpose."

Schumer has proposed that the Senate subpoena four people as witnesses to testify about the delay of nearly $400 million in U.S. military aid to Ukraine, including acting White House chief of staff Mick Mulvaney and former national security adviser John Bolton.

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McConnell, who with many other Republicans doesn't want witnesses, has said he'd like the Senate to follow the precedent set in the 1999 Senate trial of President Bill Clinton, in which there was a two-step process: an initial agreement to set a schedule and opening arguments, followed by a vote on whether to have witnesses.

The rules of a trial would require the support of a majority of the Senate — 51 senators. While the GOP has a 53-47 majority, moderate Republicans such as Mitt Romney of Utah, Susan Collins of Maine and Lisa Murkowski of Alaska could balk at rules favored by their Republican colleagues.

Even if a trial does happen, it's all but certain that Trump will be acquitted and remain in office. McConnell has said he would be surprised if there were 67 senators who would vote to remove him.

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"The case is so darn weak coming from the House," McConnell said in an interview on Fox News. "We know how it's going to end. There's no chance the president's going to be removed from office."

That doesn't mean that the process itself will result in an unalloyed political win for Trump.

"I think the final outcome is entirely predictable, but there are several wild cards that could turn this into a worse experience for the president," said Rory Cooper, managing director of the communications firm Purple Strategies, who was communications director for Eric Cantor, R-Va., when Cantor was the House majority leader.

"Senate Republicans may not allow new witnesses, but that doesn't mean new information won't come out, especially with 'loose lips' Giuliani involved," he said, referring to Rudy Giuliani, Trump's personal lawyer, who is a key figure in the Ukraine saga.

Senate to consider trade deal

The president's revamp of the North American Free Trade Agreement — the United States–Mexico–Canada Agreement, or USMCA — overwhelmingly passed the House in December, but the Senate has yet to take it up. Senate Finance Committee Chairman Chuck Grassley, R-Iowa, announced that he planned to lead a markup of the agreement on Tuesday and suggested that it would probably be ratified shortly thereafter.

After a briefing with U.S. Trade Representative Robert Lighthizer before Congress left for the holidays, Senate Republicans said they were frustrated with the process but expected that the deal would pass in the Senate after an impeachment trial.

Sen. Kevin Cramer, R-N.D., for example, called the agreement "imperfect," but he said, "At the end of the day, it's better than NAFTA, in my view."

Sen. Patrick Toomey, R-Pa., on the other hand, has signaled that he plans to oppose the agreement, telling reporters last month that "there are serious problems" because USMCA would result in "less growth, less trade and less job creation than the underlying NAFTA."

It appears, however, that a bipartisan majority is likely to ratify the agreement.

Democrats aren't done investigating

House Democrats have indicated that their oversight of Trump isn't stopping with his impeachment: They've suggested that they plan to pursue robust investigations of both the president and his administration, including sustained pushes for his financial and tax records.

"There are still a number of key investigations that Democrats will pursue, including the Trump tax returns and the steering of taxpayer dollars to Trump-owned properties," said Kurt Bardella, a former Republican staffer who was deputy communications director and senior adviser to former Rep. Darrell Issa, R-Calif., during Issa's tenure as chairman of the Oversight Committee.

Meanwhile, he said, "Supreme Court decisions, like the one that will involve the subpoena to [former White House counsel Don] McGahn, will play a large role in dictating some of these investigations."

House Democrats will likely ramp up their investigations of the administration in cases in which officials defied congressional subpoenas last year. Attorney General William Barr and Commerce Secretary Wilbur Ross, for example, ignored subpoenas requesting documents relating to the administration's decision to add a citizenship question to the 2020 census.

Compromise?

While both parties will have to compromise by the end of September on must-pass legislation like government funding and the debt ceiling, they aren't likely to find a lot of other common ground.

The Senate will continue to focus on confirming as many judicial nominees as possible, said Cooper of Purple Strategies — and the House will continue to pass bills that have no chance to make it into law but would give members up for re-election something to run on.

Lawmakers from both parties have said they want to bring down drug prices, but it's unclear whether they can nail down the details to send an agreement to the president's desk. Last year, House Democrats passed such a bill, but Cooper said a deal could be toxic for the grassroots.

On one hand, Cooper said, "Republican base voters will blindly defend anything Trump endorses" — but at the same time, "progressive Democrats are not in the mood for a bipartisan bill, and Pelosi may not feel she has enough capital to spurn them next year."

Meanwhile, the politics of passing an infrastructure agreement or a bill to restrict guns are so volatile in a presidential election year that both measures are virtual nonstarters.

2020 overshadows everything

The congressional calendar will be limited in 2020 as incumbents — and some presidential contenders in the Senate — shift their attention to running for re-election. As is typical in an election year, the House and the Senate are scheduled to be in Washington less than in off-years, spending more time campaigning in their districts.

Above all, the policy agenda and how members vote will largely be driven by the election, as Democrats aim to keep their majority in the House and as Republicans try to keep control of the Senate.

On the other hand, not everyone is looking for a return trip to Washington: More than two dozen House Republicans have already announced that they aren't seeking re-election.