WASHINGTON (AP) — With Democrats now controlling the House and holding the legal key to seeking President Donald Trump's tax returns, Republican lawmakers are invoking privacy in defending Trump's flank.

At an oversight hearing Thursday, lawmakers examined proposals to compel presidents and presidential candidates to make years of their tax returns public. And they discussed the authority under current law for the head of the House Ways and Means Committee — now Democratic Rep. Richard Neal — to make a written request for any tax returns to the Treasury secretary.

The law says the Treasury chief "shall furnish" the requested information to members of the committee for them to examine behind closed doors.

Republicans accused the Democrats of using powers in the tax law to mount a political witch hunt for Trump's tax returns.

"In reality, this is all about weaponizing our tax laws to attack a political foe," Rep. Jackie Walorski of Indiana said at the hearing by the Ways and Means oversight subcommittee.

Getting Trump's returns has been high on the Democrats' list of priorities since they won control of the House in November's midterm elections, but asking for them will probably set off a huge legal battle with his administration.

The Democrats tried and failed several times to obtain Trump's returns as the minority party in Congress, seeking to shed light on his complex financial dealings and potential conflicts of interest. Their newly energized leftward wing is pushing Neal to set the quest in motion, and fast.

Thursday's hearing appeared to set the table for the move by examining the legal foundations.

"A strong case is being built," William Tranghese, an aide to Neal, told The Associated Press this week. He said Neal is consulting with lawyers for the House "to determine the appropriate legal steps to go forward with this unprecedented request."

Rep. John Lewis, D-Ga., chairman of the oversight subcommittee, said the American public is intensely interested in the subject. "We ask the question: Does the public have a need to know that a person seeking or holding the highest office in our country obeys the tax laws?"

George Yin, a professor of law and taxation at University of Virginia Law School, testified to the panel that he doesn't see any "wiggle room" in the law for the Treasury secretary to refuse Neal's request for Trump's returns.

If the Trump administration refused the request, "We would be in uncharted territory," Yin said.

The legal battle that could ensue over Trump's tax filings would be unprecedented. It could take years to resolve, possibly stretching beyond the 2020 presidential election.

Rep. Mike Kelly of Pennsylvania, the subcommittee's senior Republican, accused the Democrats of gearing up to obtain the president's returns — and release them.

"Congress is prohibited by law from examining and making public the private tax returns of Americans for political purposes," said Kelly. "Such an abuse of power would open a Pandora's box. It would set a very dangerous precedent."

The tax returns of House Speaker Nancy Pelosi, other lawmakers or federal employees could be in jeopardy, he warned.

But Bill Pascrell, D-N.J., insisted that no one, including the president, is above the law. "The law is on our side," he said.

At a news conference Thursday, Pelosi said the public "overwhelmingly" wants to see Trump's tax returns, but the move cannot be made in haste.

"It's not just a question of sending a letter; you have to do it in a very careful way. And the chairman of the committee (Neal) will be doing that," the Democrats' leader said.

The hearing came two days after Trump faced a divided Congress in his State of the Union address, imploring the Democrats to step away from "ridiculous partisan investigations."

The subcommittee also examined a proposal that would require all presidents, vice presidents and candidates for those offices to make public 10 years of tax returns. It's part of House Democrats' comprehensive election and ethics reform package — their first major bill for the new Congress this year. The legislation also would make it easier for citizens to register and vote, and ban executive-branch officials from lobbying their old agency for two years after they leave government.

While the ethics bill includes a range of reforms, some Democrats have made clear that one of their chief targets is Trump. Some elements of the bill have bipartisan support, but the overall package is unlikely to advance in the Republican-controlled Senate.

If the administration mounted a legal challenge over Trump's returns, "I assume that there would be a court case that would go on for a period of time," Neal, D-Mass., said just after the November election.

Treasury Secretary Steven Mnuchin "will review any request with the Treasury general counsel for legality," the department has said. Trump's attorney Rudy Giuliani has suggested the Democrats could have a hard time proving their demand was intended for pursuing legitimate congressional oversight and was not a political scavenger hunt.

Trump broke with decades of tradition for presidential candidates by refusing to release his income tax filings during his 2016 campaign. He has said he won't release them because he is being audited, even though IRS officials have said taxpayers under audit are free to release their returns. Trump claimed at a news conference following the November elections that the filings are too complex for people to understand.

Democrats want to dive in and explore numerous questions about Trump’s personal financial webs. Among them: whether there are conflicts of interest between his companies and his presidential actions; what are the sources of his income and to whom he might be beholden as a result; whether he’s properly paid taxes; and whether he benefited from the sweeping Republican-written tax law enacted in late 2017.