Mitt Romney is endorsing former rival John McCain as the 2008 Republican presidential nominee fights to keep his Senate seat.
Romney said in a statement Tuesday the Arizona senator's "record of service and sacrifice for America is honored by all." The former Massachusetts governor added, "It's hard to imagine the U.S. Senate without John McCain."
McCain replied: "Gov. Romney is among the brightest and most dynamic leaders in our party, and I am proud to have his support."
Just two years removed from being his party's titular leader, McCain is facing a Republican primary challenge from former U.S. Rep. J.D. Hayworth. He complains McCain has supported big government spending and betrayed conservative values with his support for immigration reform.
Hayworth represented an Arizona House district for six terms before losing a re-election bid in 2006. He went on to work as a talk-radio host, giving him a bully pulpit to air his views.
McCain and Romney clashed bitterly in the race for the 2008 GOP nomination, especially before the Michigan and Florida primaries. After McCain pulled ahead, Romney not only endorsed him but energetically campaigned for him and dispatched top aides to help with fundraising and campaign strategy.
Yet even before McCain lost the general election to Democrat Barack Obama, Romney began laying the groundwork for a second White House campaign. He established a so-called leadership PAC so he could travel the country and dispense campaign contributions to like-minded politicians. He has also written a book — being released next week — that analyzes what he sees as faults in the Obama administration and his prescription for curing the nation's ills.
McCain's former vice presidential running mate, Sarah Palin, also has endorsed him. She and Romney are potential rivals in the 2012 presidential race.