WASHINGTON, Nov. 15 (UPI) -- U.S. Sen. John McCain, R-Ariz., expanded the field of possible 2008 Republican presidential nominees, announcing he will form an exploratory committee.
McCain is the fourth Republican to announce formation of an exploratory committee since last week's midterm elections, CNN said. He is expected to file committee registration papers with the Federal Election Commission by the end of this week.
On his Web site, McCain said the move will "continue my conversation with the American people over the direction of the Republican Party and the future of our country," CNN said.
Exploratory committees permit potential candidates to raise money without having to disclose donations or expenditures publicly.
Former New York Mayor Rudy Giuliani filed papers last week with the FEC to form a committee. Rep. Duncan Hunter of California -- the lame-duck chairman of the House Armed Services Committee -- was the first to form a committee.
Former Wisconsin Gov. Tommy Thompson -- who headed the Department of Health and Human Services during President George W. Bush's first term -- said he is considering a White House bid.
On the Democratic side, Iowa Gov. Tom Vilsack announced he will run for his party's nomination.
