Democrats have been promising oversight of the Trump administration for months if they get a House majority—and now they will have the numbers to investigate the president’s business interests, tax returns, possible Russian ties, and other matters.

Rep. Jerrold Nadler, D-N.Y., who will be House Judiciary Committee chairman when the new majority takes control in January, has big game in mind.

Nadler has talked to fellow lawmakers about impeaching both President Donald Trump over Russia and Supreme Court Justice Brett Kavanaugh over alleged perjury during his heated Senate confirmation, The Federalist reported Wednesday.

Other incoming House committee chairmen have pledged more aggressive oversight of the president as well.

Rep. Adam Schiff, D-Calif., will be chairman of the Permanent Select Committee on Intelligence and Rep. Elijah Cummings, D-Md., will lead the Oversight and Government Reform Committee.

“I want to probe senior administration officials across the government who have abused their positions of power and wasted taxpayer money, as well as President Trump’s decisions to act in his own financial self-interest rather than the best interests of the American people,” Cummings said after the midterm elections.

Given the divided Congress—Republicans will continue to control the Senate—investigating may be the only way House Democrats see having an impact.

“There aren’t many other ways to make their mark. They can’t pass legislation, so it’s hard to imagine they’re not focused on investigations,” Curt Levey, president of the Committee for Justice, a conservative legal group, told The Daily Signal. “They will likely frame it as holding the administration accountable, but their base will demand nothing short of impeachment.”

However, oversight doesn’t just involve political gotcha and can be productive in a bipartisan way, one ethics watchdog said.

“We should see a concentration on disaster relief contracts and cybersecurity,” Liz Hempowicz, director of public policy for the Project on Government Oversight, told The Daily Signal. “Most organizations have to sue to be moved up in the cue for [Freedom of Information Act] requests. We need updated rules for the Office of Government Ethics.”

“There are a ton of issues to investigate that don’t deal with the president himself, that affect everyone,” Hempowicz said. “Targeting waste, fraud, and abuse is not partisan, even if the approaches to reforms might differ.”

There is still reason to pursue headline-grabbing issues that are substantive, she said.

“I hope members of Congress can walk and chew gum at the same time,” Hempowicz said. “There is substantive bipartisan work that can be done, and they can still look at emoluments and tax returns. If there are legitimate questions about whether the president is using his office to enrich his companies, that is something Congress should be focused on.”

Based on statements by Democrats in recent months, here are six keys to upcoming House oversight of the Trump administration.

1. The New Chairmen

The three incoming chairmen–Cummings, Nadler, and Schiff—staked clear ideological agendas during their tenures in Congress.

As the ranking member of the Oversight and Government Reform Committee, Cummings routinely pushed back against two Republican chairmen, Darrell Issa of California and later Trey Gowdy of South Carolina.

This was particularly the case during the committee’s investigation into the IRS scandal, in which the tax collecting agency targeted conservative organizations during the Obama administration.

Cummings also served on the House select committee investigating the 2012 terrorist attacks in Benghazi, Libya, and whether the State Department could have taken steps to secure the U.S. compound there.

He called the investigation a “political charade” and “partisan attack.”

Cummings was among only 75 House members—all Democrats—who voted against revoking federal funding from the Association of Community Organizers for Reform Now, better known as ACORN. In a bipartisan vote in September 2009, the liberal advocacy group came under scrutiny for numerous ethical and legal issues.

However, Cummings repeatedly went after True the Vote, a Texas-based group that advocates voter ID laws across the country. He accused the organization of trying to take away the voting rights of minorities.

Nadler, incoming chairman of the Judiciary Committee, also has been involved in some controversies.

In January 2000, the New York Democrat pushed for President Bill Clinton’s last-minute pardon of Susan Rosenberg, a member of the radical Weather Underground. Rosenberg was sentenced to 58 years in prison for her role in an armed robbery in 1981.

During the George W. Bush administration, Nadler was routinely a critic of the Patriot Act and other national security measures during the war on terrorism in the aftermath of 9/11.

As for Schiff, he dismissed the Intelligence Committee’s conclusion in March that there was no collusion between Trump’s presidential campaign and Russia.

The panel’s Republican majority, the California Democrat said, “has placed the interests of protecting the president over protecting the country, and history will judge its actions harshly.”

2. More Russia

Special counsel Robert Mueller reportedly will wrap up, by year’s end, his investigation of Russian election interference and whether the Trump campaign colluded with Moscow.

“We’ll have to see what Bob Mueller has been able to do and what Bob Mueller has been able to say, either via indictment or via report, and that will also guide what we intend to do in our committee,” Schiff told MSNBC.

The Intelligence Committee would take the lead on the Russia probe in the House, but the Judiciary Committee also would play a role, Nadler reportedly said. Any impeachment move would be cleared through Judiciary.

The conclusion of the Mueller probe likely won’t make a difference in what the House does, said Levey, head of the Committee for Justice.

Levey said he suspects the report will conclude no direct evidence of collusion, but will find points on which to criticize the Trump campaign.

“The Mueller report will still be used as a justifiable starting point for impeachment, it won’t limit them,” Levey told The Daily Signal, referring to Democrats. “Even if the report finds no direct evidence, this has gone on for two years without a lot of evidence.”

3. Foreign Emoluments

Nadler already has signed onto letters inquiring about money from foreign governments doing business with Trump’s family-owned companies while he serves as president.

A president making money from foreign sources would be a violation of the Constitution’s obscure Foreign Emoluments Clause, Democrats contend.

Nadler and Sen. Richard Blumenthal, D-Conn., have led a group of almost 200 Democratic members of Congress in suing the administration to require the president to notify Congress before accepting any benefit from foreign governments.

In September, a federal district judge in the District of Columbia ruled the lawmakers have standing to bring the case.

Trump vowed before taking office to donate all foreign profits from his hotels, golf courses, and other holdings to the U.S. Treasury. However, Democrats complain, profits don’t necessarily include all revenue from foreign sources.

4. Ouster of Jeff Sessions

Trump gave House Democrats a new topic to probe Wednesday when he demanded Attorney General Jeff Sessions’ resignation.

Trump named Sessions’ chief of staff, Matthew Whitaker, as acting attorney general.

“President Trump waited until just hours after the midterm elections to make this move, which had been rumored for months,” Cummings said in a formal statement. “Congress must now investigate the real reason for this termination, confirm that Acting Attorney General Matthew Whitaker is recused from all aspects of the special counsel’s probe, and ensure that the Department of Justice safeguards the integrity of the Mueller investigation.”

Nadler and other Democrats on the Judiciary Committee wrote a letter to current Judiciary Chairman Bob Goodlatte, R-Va.

“The forced firing of Attorney General Sessions appears to be part of an ongoing pattern of behavior by the president seeking to undermine [the] investigation into Russian interference in the 2016 presidential election,” the Democratic letter says.

5. FBI Headquarters

Cummings and other Democrats on the Oversight and Government Reform Committee have inquired whether the Trump administration blocked the sale of the 44-year-old FBI headquarters building to prevent competition for the Trump Organization’s Washington hotel.

The FBI has been considering moving to a new location, likely in Maryland. The White House previously said the reason for nixing the sale was to save taxpayers money.

“These new documents raise serious questions about whether Ms. Sanders issued her statements with knowledge of these facts or, alternatively, without taking basic steps to confirm their accuracy,” Cummings and the other Democrats wrote. “Either way, the White House should not be issuing false claims to justify or conceal President Trump’s conflicts of interest on this matter.”

House Democrats released emails showing what they contend is evidence White House officials were aware that the Trump plan would cost taxpayers millions of dollars more than the longstanding relocation plan for FBI headquarters.

A report by the General Services Administration’s Office of Inspector General concluded that relocating the FBI to the Washington suburbs would cost an estimated $3.6 billion, and selling the existing building on Pennsylvania Avenue NW to commercial developers or others could result in revenue of $334 million to help offset that cost.

The Trump administration floated an alternative, $3.8 billion plan to keep the Pennsylvania Avenue property, demolish the existing facility, and construct a new building, according to the inspector general’s report.

That cost would include $3.3 billion to rebuild, $57 million to relocate 2,306 FBI personnel who will not fit in the Pennsylvania Avenue facility, and $459 million in construction costs at FBI facilities in Alabama, Idaho, Virginia, and West Virginia to accommodate those employees.

6. Total of 64 Subpoenas and Counting

Democrats on the House Oversight Committee have requested 64 subpoenas since Trump came into office that the Republican majority decline to issue.

Among those 64 motions were efforts to obtain information on:

—Separating children from adult illegal immigrants who cross the border into the U.S.

—How the White House grants security clearances.

—The Justice Department’s decision not to defend the Affordable Care Act, better known as Obamacare.

—The Census Bureau’s intention to ask about citizenship on the 2020 census.

—Operations of the Trump Foundation charity.

—Business holdings of presidential son-in-law Jared Kushner and his wife, Ivanka Trump.