Former Sen. Lincoln D. Chafee, who left the GOP last year and later endorsed Democrat Barack Obama for president, has signed on with Republicans for Obama, saying that the Illinois senator embodies “my kind of traditional conservatism.”

During a conference call with reporters yesterday, Rhode Islander Chafee, former Iowa Rep. Jim Leach, and a former GOP fundraiser and adviser to President Bush, Rita Hauser of New York, told how they will try to build support for the presidential candidate among Republicans and independents.

The Republican National Committee quickly responded to the Obama campaign’s promotion of Republicans for Obama with an e-mail to reporters that carried news accounts about Obama’s liberal Senate voting record. The RNC statement said Obama has a “weak record on bipartisanship.”

Chafee, who made news in 2004 by announcing that he had cast a write-in protest vote against Mr. Bush, was perhaps the most liberal Senate Republican during his tenure and the only one that that voted against the president’s Iraq war resolution in 2002.

While it’s true that he left the party, Chafee said, his “Republican credentials are sincere.” During his Senate tenure, Chafee often held out Arizona Sen. John McCain, now the Republican presidential candidate, as a model of bipartisanship. McCain, for his part, supported Chafee’s unsuccessful bid for reelection in 2006. But Chafee said yesterday that there are “two different John McCains.” For example, he contrasted McCain’s early opposition to the Bush tax policies to his current opposition to letting Bush tax cuts expire.

Chafee did not respond when a reporter asked whether he and Leach and Hauser will attend the Democratic National Convention in Denver this month. An Obama campaign spokesman said there was no announcement to be made on that score.

— John E. Mulligan, Journal Washington bureau