WASHINGTON -- From steel tariffs to Alaskan oil drilling, Republicans and business interests are building alliances with union workers that could affect where and how organized labor provides support in the fall congressional elections.

The latest example came Thursday when traditional rivals, the U.S. Chamber of Commerce and the AFL-CIO, joined to lobby for an overhaul of immigration laws. Both want to win legal status for millions of illegal immigrants now working in the United States.

Chamber President Thomas Donohue and AFL-CIO President John Sweeney stood side by side to announce the alliance.

"A few years ago people would have said those people will never be on a platform together unless they're arguing with one another," Donohue said.

Common ground

Immigration is one of several issues that have brought together the Republican-leaning Chamber and the AFL-CIO, one of the Democratic Party's key constituents.

They also want Congress and President Bush to provide health care coverage for the uninsured. On Wednesday, they filed court arguments together against new campaign finance restrictions.

The teamwork comes as the Republican president and labor unions also find more common ground.

A solid majority of union members backed Democrat Al Gore in the 2000 presidential election that Bush narrowly won.

Since then, Bush and unions have pushed to expand coal mining and open the Arctic National Wildlife Refuge to oil drilling, and have supported safety standards for Mexican trucks entering the United States in addition to tariffs to protect the U.S. steel industry.

Bush this week stood beside business executives and labor leaders to urge Congress to approve government-backed terrorism insurance to get construction projects rolling again.

The Bush administration has relaxed financial oversight of the Teamsters union that had been prompted by a corruption investigation. In a symbolic gesture, Bush also reserved a seat for Teamsters President James P. Hoffa at the State of the Union address in January.

The efforts could have implications for the fall election for control of Congress and beyond, experts said.

Unions, which ran millions of dollars of issue ads since 1996 aimed at unseating Republicans, may find their members less inspired to campaign for Democrats or against Republicans.

"What it mostly means is they don't have a strong motivation to go out there and punish the Republicans because of the president," said Charles Jones, a University of Wisconsin political science professor.

Some blue-collar workers, a constituency Ronald Reagan successfully courted two decades ago, agree.