The chairman of the House Ways and Means Committee wants to cut the top U.S. tax rate to 25% for individuals and corporations, and cut or eliminate many popular deductions.

The odds of quick action appear slender. But the move, from Rep. Dave Camp (R., Mich.), is significant as a marker in what will likely be a multiyear debate over revamping the tax code. The plan also provides Republicans with a position to pitch in the 2012 election, a campaign that promises to focus heavily on the economy and jobs.

Mr....