WASHINGTON • President Barack Obama's proposal to lower the corporate tax rate to 28 percent from 35 percent shows a growing consensus in Washington that many companies need to pay less in taxes for the U.S. to stay competitive globally.

But exactly how to do that — and which companies should pay more to make up the difference — remains elusive in a volatile election year.

Democrats and Republicans have starkly different ideas about how far to lower corporate tax rates and whether changes to individual tax rates, including the Bush-era cuts that expire at the end of the year, should be part of the reform debate.

Obama laid down his marker Wednesday with a 23-page framework for a plan to eliminate dozens of breaks for specific industries, particularly oil and gas production, and new incentives for domestic manufacturing and alternative energy.

"Our current corporate tax system is outdated, unfair and inefficient," he said. "It provides tax breaks for moving jobs and profits overseas and hits companies that choose to stay in America with one of the highest tax rates in the world."

Key Republicans welcomed Obama's call for a lower corporate rate. But they said his proposal wouldn't reduce the rates enough and that his broad framework needed much more detail.

"It's official: President Obama, congressional leaders of both political parties and the Republican candidates for president all support lowering corporate tax rates," said John Engler, president of the Business Roundtable, a top industry trade group. "Now let the debate begin."

Legislative action on taxes probably will have to wait until after the November elections because the topic is tightly intertwined with key campaign issues, including how best to boost job creation, how to limit the growing size of government and whether large corporations and wealthy individuals are paying their fair share.

Highlighting the political stakes, Republican presidential candidate Mitt Romney chose Wednesday to release a tax plan of his own, one that called for slashing individual rates by one-fifth. He had previously called for a deeper corporate tax rate cut, to 25 percent, which is the same as proposed by a key House Republican.

Other Republican presidential candidates want to go further. Rick Santorum is calling for a 17.5 percent corporate rate, and Newt Gingrich wants it to drop to 12.5 percent.

Engler, as well as Thomas Donohue, president of the U.S. Chamber of Commerce, criticized Obama's plan for not lowering taxes on foreign earnings. Both industry groups want corporate profits abroad to be taxed only by the country in which they are earned. The U.S. now taxes those earnings when they are brought back to the country.

Obama rejected that idea.

Instead, he proposed a new minimum tax rate for foreign earnings.