By Katie Bo Williams, The Hill-

Russia’s involvement in the U.S. election will take center stage in Washington on Thursday with two separate hearings in the Senate – including one behind closed doors.

The Senate Armed Services Committee will hear from intelligence officials in public hearings in the morning, while the Senate Foreign Relations Committee will receive a classified briefing behind closed doors in the afternoon.

President-elect Donald Trump has repeatedly rejected assertions from the intelligence community that Moscow attempted to influence the election by hacking the Democratic National Committee and the email of John Podesta, Hillary Clinton’s campaign manager.

In a series of tweets this week, he accused intelligence officials of delaying a briefing until Friday in order to build a case against Russia – an allegation rejected by other officials. He also appeared to side with Wikileaks founder Julian Assange, who released emails believed to have been hacked by Russia. Trump noted that Assange has asserted that the emails did not come from Russia, while repeating that anyone could have hacked the DNC.

Trump’s comments have put Republicans in a tough spot, underlining the more friendly approach he has taken with Russia and more critical approach with U.S. intelligence agencies.

It has provided an opening for Democrats who hope the story about Russia will shadow the beginning of Trump’s presidency, complicating his legislative agenda.

Here are five things to watch for on Thursday.

1. How many Republicans will criticize Trump’s stance?

The Armed Services hearing is led by Sen. John McCain (R-Ariz.), who has repeatedly feuded with Trump and is deeply suspicious of Russia.

McCain’s committee will grill Director of National Intelligence James Clapper, National Security Agency and U.S. Cyber Command head Adm. Michael Rogers and Under Secretary of Defense for Intelligence Marcel Lettre.

McCain is unlikely to differ with intelligence officials who say there’s no doubt that the Kremlin was behind hacks on the DNC and other Democratic political organizations -and that it was attempting to interfere in the election.

Another member of the panel, Sen. Lindsey Graham (R-S.C.), is also a Trump critic who has warned that he would have trouble backing any of Trump’s cabinet nominees who do not accept the intelligence committee’s assessment.

Most Republicans, however, have signaled they do want to get into a battle with Trump over the issue. Many have criticized the Obama administration for allowing the hacks, while simultaneously avoiding criticism of the president-elect for disparaging the intelligence community.

At Thursday’s public hearings, GOP criticism may be centered on the Obama White House and Russian President Vladimir Putin. Many called for broader punishments than the sanctions levied by Obama last week.

An early decision for Trump will be whether he wants to lift those sanctions. He’s made clear he wants a closer relationship with Putin, and he applauded the Russian leader for not retaliating with counter-sanctions.

2. How strong is the evidence that Russia hacked the DNC?

Thursday morning’s panel could provide clues as to how intelligence agencies determined that two Russian intelligence agencies were behind the breach.

Security experts widely derided a joint Homeland Security Department-FBI report released last week that purported to give technical indicators linking Russia to the breaches, calling it over-broad and “a mess.”

Private security firms, like the company the DNC hired to investigate the hack, have gone much further in their published forensics analyses.

That evidence is very strong, outside experts say.

And Russia is widely known to conduct the kind of “active measures” the administration has accused it of using in this case.

Lawmakers will also likely probe officials on how the documents came into Assange’s hands. Critics have raised fears that the Russian government was able to “weaponize” WikiLeaks to carry out information warfare.

3. What evidence does the IC have that Putin wanted to assist Trump?

The CIA reportedly believes that Russia was explicitly trying to help Trump – raising politically explosive questions about the degree to which it succeeded.

Publicly, the administration has been much more circumspect.

“President Obama and this administration is 100 percent certain in the role that Russia played in trying to sow discord and confusion and getting involved, through the cyber domain, in our electoral process,” State Department spokesman John Kirby told CNN Tuesday.

Reports of the CIA’s stronger assessment are based on anonymous leaks to a number of publications.

The leaks have given ammunition to critics who say the Obama administration is trying to undercut Trump before he takes office on Jan. 20.

“There are real questions about why there have been so many leaks over the last seven or eight weeks from the administration about the motivations or the intentions of Vladimir Putin or other foreign leaders,” Cotton said Tuesday.

“Something our intelligence agencies and the administration ought not be doing is leaking intelligence for political or purposes or putting it in the media without any kind of official basis.”

Several lawmakers with access to intelligence have argued that while Russia may have attempted to create confusion and distrust in the democratic process, there’s no evidence it worked to elect Trump.

4. How much will the public get to see – and when?

Clapper, Rogers and Lettre will be under pressure to provide a “smoking gun” linking Russia to the alleged influence campaign.

Lawmakers have already been briefed privately by intelligence officials, but they will doubtless seek more details in an open setting on Thursday.

The Obama administration has been under fierce pressure to substantiate its claims.

The intelligence community is reportedly delivering its final, classified assessment of the campaign to Obama on Thursday, which the White House has said it will provide to lawmakers as soon as possible.

But it remains unknown how much of that document will be declassified and released to the public. The White House has said it will make public as much as it can.

5. How much will either committee be able to do?

It’s unclear how much traction any push for a more aggressive response to Russia will get.

Senate and House leadership have treated the issue cautiously, granting responsibility to the notoriously secretive intelligence committees.

The move has led critics to accuse them of trying to silence the issue – and has made it difficult for other Republicans to take action.

McCain earlier in the week signaled that he was backing off of a push to establish a select committee to investigate the matter, citing a lack of support from leadership.

Democrats have tried to establish an independent commission to push the investigation into the daylight.

“It is essential that this commission be established outside of Congress, as that is the only way to ensure that the investigation is comprehensive and not siloed within a certain congressional committee’s jurisdiction,” a group of former senior intelligence and foreign policy officials wrote Wednesday in support of such a commission.