Lost in all the rancor among Republicans over the National Security Agency’s surveillance programs has been this: A similar ideological divide has been exposed in the Democratic Party that could pose even more political difficulties for President Obama.

Several Democrats from the party’s civil liberties wing — the mirror image of the Republicans’ rising libertarian strain — met with Obama and Republican lawmakers Thursday at the White House to discuss concerns about the NSA’s phone data collection program and elements of the administration’s broader surveillance effort.

Among them were Democratic Sens. Mark Udall (Colo.) and Ron Wyden (Ore.), the lawmaker who earlier Thursday proposed legislation that would, in addition to other measures, add a privacy and civil liberties advocate to the secret court proceedings when the government requests national security warrants.

Now government lawyers make the case for warrants before the Foreign Intelligence Surveillance Court, which has turned down only 11 of the government’s nearly 34,000 warrant requests over the past three decades.

Sen. Richard Blumenthal (D-Conn.), one of the bill’s co-sponsors, suggested that the Obama administration supports the proposal, although White House officials declined to take a position publicly.

Sen. Chuck Schumer (D-N.Y.) said Russian President Putin’s decision to grant NSA leaker Edward Snowden year-long asylum has put the U.S. relationship with Russia in great danger, and that President Obama should consider moving the G-20 summit out of the country. (Nicki Demarco/The Washington Post)

“We’re in conversation with members of Congress about various ideas and will continue to do that,” White House press secretary Jay Carney told reporters Thursday. “As the president has said, [we will] continue to take steps to improve the effectiveness of these programs, working with Congress.”

A former constitutional law lecturer, Obama came to office pledging to ensure that his national security policies complied not only with the law but also with what he called American traditions that respect human rights and civil liberties. But his record has been mixed, as he acknowledged in a May speech at the National Defense University, and many supporters have expressed concern particularly about his expansion of surveillance programs started during the George W. Bush-administration.

The widespread uneasiness on the left was underscored last week during the House vote on whether to defund the NSA’s phone record collection program.

Much was made of the fact that nearly half of Republicans were in favor of the measure, despite a tradition in the post-Sept. 11, 2001, era of supporting such programs. It is perhaps equally notable that 111 of 194 House Democrats backed the measure, defying the Obama administration in doing so.

Unlike the Republican libertarian wing, Democrats who hold similar views on surveillance are largely in search of a leader. There isn’t single figure on the left who is speaking to those civil liberties concerns with the same force that Sen. Rand Paul (Ky.) is on the right.

For now, the de facto leaders of the left’s effort to rein in the Obama administration’s surveillance programs are Wyden and, arguably, Glenn Greenwald, the journalist who has been working with Edward Snowden to reveal the programs. Although the two have been pushing the issue hard, they aren’t necessarily figures with significant built-in constituencies.

Sen. Dianne Feinstein (D-Calif.), who also attended Thursday’s White House meeting, has been talking about ways to amend the programs, working as a bridge between libertarian-leaning Democrats and the Obama administration.

The debate within the Democratic Party has occurred largely under the radar, and no potential 2016 Democratic presidential candidates have taken up the mantle in the way Paul has among Republicans, despite polling that shows a sizable constituency for just such a candidate.

A Washington Post-ABC News poll last week showed similar levels of privacy concerns in both parties, with more than six in 10 liberal and moderate Democrats saying the NSA’s surveillance programs intrude on Americans’ privacy.

Privacy concerns in the Democratic Party have waned since Obama took office, but there remains a large number of voters for a potential 2016 contender to win over. That is particularly true given that former secretary of state Hillary Rodham Clinton and Vice President Biden are closely associated with the administration’s national security programs and lead the field of likely candidates.

Julian Sanchez, a research fellow at the libertarian Cato Institute, said Wyden is doing yeoman’s work but acknowledged that he’s “not really a rabble-rouser in the mold of someone like Rand Paul.”