Richard Neal, a Massachusetts Democrat who is the incoming chairman of the House Ways and Means Chairman, has said Democrats plan to seek Trump’s tax returns . Trump broke from a decadeslong tradition when he refused to release them. Why he did that has been a mystery. Questions have increasingly been raised about whether Trump’s business dealings are intertwined with his campaign and actions in office. The tax returns could shed light on that issue.

The Democrats are taking over the House of Representatives Thursday and planning to investigate President Trump, a Republican, and his administration on a variety of fronts. Here’s a rundown of some of their top targets:


Possible collusion with Russia

Adam Schiff, the incoming House Intelligence Committee chairman, said on MSNBC his committee plans to revive its investigation into possible collusion between the Trump campaign and the Russians, who wanted Trump to win the election in 2016. He said a “pretty damning portrait” has already emerged of contacts between Trump campaign officials and Russians “and even now we don’t see all the pieces.” He told NPR, “We will pursue the investigation indeed.”

Emoluments

Elijah Cummings, incoming House Oversight Committee chairman, plans to look into the question of whether Trump is profiting personally from being in office. He told CNN, “That’s one of the things we want to look into. We want to look and see exactly what’s happening, exactly how much money is going into his pocket, and try to make a determination whether he’s making decisions in the interests of the American people or his own bottom line.” Trump already faces a lawsuit brought by the states of Maryland and Virginia, and a lawsuit brought by members of Congress that claims he has been receiving gifts or payments from foreign governments (e.g. by their patronizing his Washington hotel), in violation of the constitutional ban on receiving such “emoluments.”


The US response to the killing of Jamal Khashoggi

Schiff told the Washington Post in November that his committee would be “delving further” into the murder of Washington Post columnist Jamal Khashoggi at the Saudi consulate in Istanbul. The CIA says the Saudi crown prince ordered the slaying. Trump has cast doubt on that finding, saying the prince might have had knowledge of the murder but adding, “maybe he did, and maybe he didn’t!”

Supreme Court nominee Brett Kavanaugh

Jerrold Nadler, incoming House Judiciary Committee chairman, told CNN that he wants to look into whether the FBI properly investigated claims of sexual misconduct that came to light during the nomination process, before Kavanaugh was approved for the Supreme Court. Nadler said he wanted to make sure there was no White House interference with the FBI probe.

Family separations at the border

Cummings’s committee, which has wide-ranging oversight powers, is also inquiring into the Trump administration’s policy, announced in April, of separating children from their families at the border, which caused a firestorm of controversy.

Matthew Whitaker

Nadler told CNN that the Judiciary Committee’s very first move would be to call Matthew Whitaker, the acting attorney general, to testify. Nadler said the goal was to protect the Trump-Russia investigation by special counsel Robert Mueller, saying the “appointment of Whitaker, who is a complete political lackey, is a real threat to the investigation.” He said congressmen would ask Whitaker how he can supervise the Mueller investigation considering his previous comments that were critical of it. “We will, if we have to, subpoena him and we will ask him, basically, about protecting the Mueller investigation,” Nadler told USA Today on Wednesday. Nadler has also said he has “very serious concerns” about William Barr, Trump’s nominee to serve as attorney general.


Various other issues

The Washington Post reported in November that other issues the Democrats are expected to probe include the hush money payments to Stormy Daniels and Karen McDougal, who alleged they had affairs with Trump; and the policy on security clearances at the White House, where Trump son-in-law Jared Kushner works without one.

Schiff has said his committee will also look into possible money laundering by Trump before he was elected and possible foreign funding of Trump’s inauguration.

Cummings’s committee is also seeking information in other areas, including the federal response to hurricanes that devastated Puerto Rico and the Virgin Islands; travel by White House and Cabinet members; White House officials’ use of personal e-mail; and former EPA administrator Scott Pruitt, who resigned after being dogged by ethics questions.