VINEYARD HAVEN, Mass. - President Barack Obama says Republicans should join him in opposing a Supreme Court ruling that vastly increased how much corporations and unions can spend on campaign ads.

Instead, the GOP wants to "keep the public in the dark" about who's behind the expenditures, Obama charged in his weekly radio and Internet address, released Saturday as he vacationed on Martha's Vineyard.

"You'd think that reducing corporate and even foreign influence over our elections wouldn't be a partisan issue," said Obama. "But the Republican leaders in Congress said no. In fact, they used their power to block the issue from even coming up for a vote.

"This can only mean that the leaders of the other party want to keep the public in the dark," said the president. "They don't want you to know which interests are paying for the ads. The only people who don't want to disclose the truth are people with something to hide."

Senate Minority Leader Mitch McConnell, R-Ky., scoffed at the president's message.

"Americans want us to focus on jobs, but by focusing on an election bill, Democrats are sending a clear message to the American people that their jobs aren't as important as the jobs of embattled Democrat politicians," McConnell said. "The president says this bill is about transparency. It's transparent all right. It's a transparent effort to rig the fall elections."

At issue is the ruling earlier this year in the case known as Citizens United that freed big businesses and unions to spend their millions directly to sway elections for president and Congress.

The ruling, seen as mostly benefiting Republicans, reversed a centurylong trend of limiting the political muscle of corporations, organized labor and their massive war chests.

In response, majority Democrats in the House passed legislation in June limiting the ruling's reach, including requiring greater disclosure by donors. But Republicans in the Senate have blocked the legislation. That doesn't appear likely to change, notwithstanding the president's pleas.

Republicans devoted their weekly address to accusing Democrats of out-of-control spending and taxing, arguing in favor of slashing government expenditures instead.

"If we keep spending too much, borrowing too much and taxing too much - if we keep doing the same things, we're going to get the same dismal results," said Rep. Charles Djou, R-Hawaii. "It's time to change direction. It's time to listen."