The White House is riding to the rescue of House Democrats’ beleaguered push for a campaign finance reform package, releasing an official endorsement Monday as President Barack Obama’s pollster issued an analysis showing “overwhelming” popular support for it.

The new focus on the DISCLOSE Act from the other end of Pennsylvania Avenue came after a bruising week for Democratic leaders trying to shepherd the bill through the House. And a House Democratic leadership aide said it represented the leading edge of a push by the administration to get the measure through Congress.

“They’re fully engaged,” the aide said.

The bill would roll back a controversial Supreme Court ruling in January that struck down limits on corporate political spending by bulking up disclosure requirements for outside groups shelling out for campaign activities.

Democratic leaders ran into trouble last week when they added a carve-out from the bill’s sunlight provision that was tailored to earn the neutrality of the National Rifle Association. As other affected groups across the political spectrum cried foul, members of the Blue Dog Coalition and Congressional Black Caucus revolted, forcing leaders to scotch floor consideration slated for Friday.

The White House in its endorsement called the bill “a necessary measure so that Americans will know who is trying to influence the Nation’s elections.” And while the Obama administration made it clear that it is no fan of the NRA carve-out, it argued the broader package is too important to set aside.

“This bill is not perfect,” the statement said. “The Administration would have preferred no exemptions. But by providing for unprecedented transparency, this bill takes great strides to hold corporations who participate in the Nation’s elections accountable to the American people.”

Obama denounced the high court decision in dramatic fashion: With Supreme Court justices seated before him during his State of the Union address this year, he said the ruling would “open the floodgates for special interests — including foreign corporations — to spend without limit in our elections.”

His pollster, Joel Benenson, made the case in a memo to Democratic lawmakers on Monday that the measure is a political no-brainer. His research found that 80 percent of voters oppose the Supreme Court ruling and that “few voters and even fewer Independents” sympathize with arguments for the decision on free-speech grounds. The Benenson memo points to “strong bipartisan support” for elements of the bill, including 77 percent backing for “strengthening political spending disclosure laws to ensure Americans can see the details of how corporations or other organizations are spending money to influence elections.”

The polling behind the memo was all conducted before Democratic leaders crafted the NRA compromise language last week, however, and it is not clear whether interest group attacks on the package will move the needle.

The U.S. Chamber of Commerce — one of the measure’s most powerful and vocal foes — launched its first paid salvo on the subject Monday, kicking off a week of full-page ads in Beltway publications saying the bill would “corrupt our democracy.” And other groups across the political spectrum remain opposed — including the American Civil Liberties Union, which outlined its concerns in a six-page letter to Members.

Meanwhile, Rep. Chris Van Hollen (Md.) — chairman of the Democratic Congressional Campaign Committee and the lead sponsor of the act — has been hustling to make the sale with his colleagues, logging 50 phone calls to fellow Democrats over the weekend, according to an aide.

Van Hollen, who also serves as Assistant to the Speaker, has been in talks with Rep. Donna Edwards (D-Md.) about broadening the NRA exemption — which leaders already tweaked again last weak, lowering the membership threshold to 500,000 for groups to qualify. But government reform groups oppose Edwards’ proposal, aimed at leveling the playing field for 501(c)(4) organizations by removing the membership threshold entirely. An Edwards spokesman declined to comment about the state of those talks, and leadership sources signaled that top House Democrats are inclined to press ahead with the targeted exemption.

The CBC, of which Edwards is a member, remains key to unlocking majority support for the bill. But senior Democrats hope the engagement of the White House will give political cover to African-American lawmakers nervous about supporting a measure with a provision tailored for the gun lobby. And to ease concerns among Blue Dogs and others that the House will tackle a bill opposed by business groups only to see it stall in the other chamber, Democrats are working to secure a statement from Senate Majority Leader Harry Reid (D-Nev.) and Senate Democratic Conference Vice Chairman Charles Schumer (N.Y.) pledging follow-through on their side of the Dome.

Van Hollen’s office on Monday circulated a memo to House Democrats laying out arguments for the bill, which it called the toughest campaign finance measure since the Bipartisan Campaign Reform Act of 2002. The memo invokes BP’s part in the Gulf Coast oil spill disaster to help make the pitch.

“Unless we act, there is nothing to stop foreign companies like BP from funneling millions of dollars into some group like ‘Americans for Clean Oceans,’ to secretly fund advertising against every member of Congress — Republican or Democrat — who tried to hold the company accountable,” it reads.

And the letter points to plans by the chamber to spend $50 million to advertise in the midterm elections. “Under the DISCLOSE Act, the American people will know what special interests are underwriting these ads. If you have nothing to hide, you have nothing to fear,” the memo reads.