WASHINGTON — Some Republicans are hoping lawmakers will soon wrap up investigations into Russian meddling in the 2016 election that have dragged on for most of the year. But with new details in the probe emerging almost daily, that seems unlikely.

Three congressional committees are investigating Russian interference and whether President Donald Trump’s campaign was in any way involved. The panels have obtained thousands of pages of documents from Trump’s campaign and other officials, and have done dozens of interviews.

The probes are separate from special counsel Robert Mueller’s investigation. Mueller can prosecute for criminal activity, while Congress can only lay out findings, publicize any perceived wrongdoing and pass legislation to try to keep problems from happening again. If any committee finds evidence of criminal activity, it must refer the matter to Mueller.

All three committees have focused on a June 2016 meeting that Trump campaign officials held in Trump Tower with a Russian lawyer and others. They are also looking into outreach by several other Russians to the campaign, including involvement of George Papadopoulos, who pleaded guilty this month to lying to the FBI as part of Mueller’s probe. New threads continue to emerge, such as a recent revelation that Donald Trump Jr. was messaging with WikiLeaks, the website that leaked emails from top Democratic officials during the campaign.

A look at the committees that are investigating, and the status of their work when they return from their Thanksgiving break:

SENATE INTELLIGENCE COMMITTEE

The Senate intelligence panel, which has been the most bipartisan in its approach, has interviewed more than 100 people, including most of those attending the Trump Tower meeting. Chairman Richard Burr of North Carolina and the panel’s top Democrat, Virginia Sen. Mark Warner, have said they plan to bring in Donald Trump Jr. The president’s son was one of several Trump campaign officials in the meeting.

The committee has looked broadly at the issue of interference, and called in executives from Facebook, Twitter and Google, pushing them to take steps to prevent Russian election meddling on their platforms. Warner told The Associated Press the committee is still looking for more information from those companies, which were initially reluctant to cooperate.

Burr has said that he wants to wrap up the probe by early spring, when congressional primaries begin. While there are many areas of bipartisan agreement on the meddling, it’s unclear whether all members will agree to the final report. It’s also unclear if the report will make a strong statement on whether the Trump campaign colluded in any way with Russia.

Warner said it’s plain there were “unprecedented contacts” as Russians reached out to the Trump campaign but what’s not established is collusion.

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HOUSE INTELLIGENCE COMMITTEE

In the House, Democrats hope the intelligence committee can remain focused on the Russia probe as the panel’s GOP chairman, Rep. Devin Nunes, and other Republicans have launched new, separate investigations into Democrat Hillary Clinton and a uranium deal during President Barack Obama’s administration. Nunes stepped back from the Russia probe in April after criticism that he was too close to the White House, but remains chairman of the committee.

Some Republicans on the panel have grown restless with the probe, saying it has amounted to a fishing expedition and pushing for it to end. Still, the committee has continued to interview dozens of witnesses involved with the Trump campaign, among them several participants in the 2016 meeting. On Nov. 30, the panel will interview Attorney General Jeff Sessions behind closed doors. Lawmakers are interested in Sessions’ knowledge about interactions between Trump campaign aides and Russians, and also his own contacts.

The top Democrat on the panel, California Rep. Adam Schiff, told AP the committee has multiple interviews before the New Year. He said the Republican investigations into Clinton and Obama could be “an enormous time drain,” but they have not yet fully organized. He says the committee must be thorough and he doesn’t believe the Russia investigation should end soon.

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SENATE JUDICIARY COMMITTEE

The Senate Judiciary Committee has also divided along partisan lines as Chairman Chuck Grassley, R-Iowa, and California Sen. Dianne Feinstein, the panel’s top Democrat, haven’t agreed on some interviews and subpoenas. But as in the House, the panel has proceeded anyway, conducting bipartisan, closed-door interviews with several people who were in the 2016 meeting.

The panel is showing recent signs that it is aggressively pursuing the investigation. The committee is the only one to have interviewed Trump Jr. And just before the Thanksgiving break, it sent Trump’s son-in-law, Jared Kushner, a letter asking him to be more forthcoming with the committee.

Grassley has been focused on a law that requires foreign agents to register and the firing of James Comey as FBI director. Along with the other committees, Judiciary is also looking into a dossier of allegations about Trump’s own connections to Russia.

It’s not known if the panel will issue a final report, or if its probe will conclude before next year’s elections.