Senate Democrats on Thursday turned a meeting on President Trump's nominee to lead the IRS into a referendum on President Trump's behavior toward Russia, and said the Senate should use the nomination as leverage over Trump.

The nominee, Chuck Rettig, was cruising toward gaining bipartisan approval from the panel in a vote scheduled for the Senate Finance Committee on Thursday. But Democrats, who acknowledged that Rettig is qualified for the job, sought to stop his progress based on several of the week's developments related to Russia's influence in the U.S. Ultimately, Republicans were only able to advance the nomination on a 14 to 13 vote Thursday afternoon.

The tipping point, according to Democrats, was Treasury's decision on Monday to allow some political nonprofit groups to disclose less information about donors to the IRS.

That action, Democrats argued, will allow more foreign "dark money" in politics. They raised the prospect that it could allow Russia to spend on elections, noting the federal indictment this week charging a Russian NRA member of being an agent of the Kremlin.

"The Trump administration has taken a qualified nominee and dumped him right in the middle of a dark money political firestorm of their own creation," said Ron Wyden, the ranking Democrat on the committee. "And a radical change in tax law regarding transparency and disclosure has dragged the IRS and Treasury into a swirling set of questions about the president’s foreign financial ties and motivations."

Wyden was one of several Democrats who said he'd vote against Rettig even though he believed he was qualified.

Democrats pressed the chairman, Orrin Hatch of Utah, to halt the committee vote to push back against the Trump administration.

Hatch denied the request and called for a vote later in the day. "You’re not hurting anyone except for the American public by not voting for him," Hatch said.

The committee meeting adjourned without a vote on Rettig's nomination, but the committee could vote later in the day.

Several Democrats also cited Trump's performance at a press conference with Russian president Vladimir Putin in Helsinki Monday as cause for alarm, and said that should prompt the committee once more to push for the president's tax returns.

[More: Trump says he misspoke, accepts US intelligence on Russian meddling]

"I think it is time," Democrat Mark Warner of Virginia said of having the committee review Trump's tax returns. "We have a cloud that hangs over this whole administration over this moment in time."

Rettig, a Beverly Hills tax lawyer who has represented clients in conflict with the IRS, faced little Democratic skepticism during committee hearings. He has said that his goal as commissioner would be to rebuild trust between the agency and Congress and the public.

Currently, the IRS is being run on an acting basis by David Kautter, who is also assistant secretary of the Treasury for tax policy.

This post has been updated with the results of the committee vote.