Possible candidates for the White House in 2012 have stepped up their jockeying for position, not just in a string of high-profile public events over the past few days but also out on the political battleground, building a power base by endorsing candidates and fund-raising for the imminent midterm elections.
While prominent Republicans, including Sarah Palin, courted party loyalists with appeals to the anti-government Tea Party movement and to conservative "values voters", New York's Mayor, Michael Bloomberg, stoked speculation of an independent run for the presidency by revealing he has been fund-raising for moderates of both sides.
The billionaire business owner, who won a third term in New York last November, flirted with a White House bid in 2008 but stood aside after Barack Obama won the Democratic Party nomination with an appeal to the independent, centrist voters that Mr Bloomberg wanted to represent.
The return to poisonous partisan politics, and the rightward drift of the Republican party under the Tea Party's influence, has reopened space for Mr Bloomberg, and he has been hosting fund-raisers for candidates including Harry Reid, the Leader of the Democrats in the Senate, who is under pressure from a Palin-endorsed Tea Party candidate in Nevada, and Meg Whitman, the Republican former eBay chief executive, who is in a tight race for the governorship of California.
Mr Bloomberg ruled out a bid for the White House in an interview with The New York Times this weekend, but described himself as "a doer" who was casting round for a role after his New York term expires in 2013.
On the Republican side, potential rivals for the party's nomination have lined up on different sides of individual races in the primaries for the midterms. Sarah Palin's endorsement of Christine O'Donnell, an otherwise unknown candidate, led to her upset win of the Republican nomination for the Senate race in Delaware. Mike Huckabee, the evangelical pastor who came close to upsetting John McCain in the race for the Republican nomination for the presidency in 2008, has also been backing candidates.
In Iowa, the touchstone state which votes first in the primary season in 2012, all the potential Republican candidates descended for an event to celebrate the late Ronald Reagan. Ms Palin, whose presence ensured that the annual dinner was the best attended ever, called for party unity and for an embrace of Tea Party's anti-tax, anti-spending agenda. And she stoked speculation about her intentions for 2012, making the joke that she had decided not to go out jogging so as to avoid the headline "Palin in Iowa, decides to run".
Also over the weekend, conservatives gathered in Washington for the "values voters" summit, where they put a new name into the frame: Mike Pence, a House of Representatives Republican, who won the event's straw poll for 2012. Even with the midterm elections looming in six weeks, it was speculation over the prospects for the presidential race which dominated political discussion on the Sunday talk shows.
The former Republican secretary of state Colin Powell promised to fight to bring the party back to the political middle, and kept his praise for Ms Palin as faint as possible. "I didn't think she was ready to be President in 2008 and I'm not sure she will be in 2012, but there is nothing wrong with Sarah Palin getting out there, presenting her views, animating American political life," he told NBC's Meet the Press. "She's a star."
The columnist Bill Kristol, credited with being among the first to spot Ms Palin's potential, kept her as his top tip for 2012, with Mitch Daniels, Indiana Governor, as a close second. On Fox News, he said the party should nominate "someone new, someone different", and not an establishment politician.
Republican contenders: The men likely to go into battle with Sarah Palin
A proven and competent technocrat, Romney's appeal is complicated by his status as a practicing Mormon. There are concerns that this might alienate Christian conservatives and scare off swing voters.
A father-figure of the conservative movement since the 1990s, Gingrich commands respect from both grassroots and the Republican elite. One concern is his age; by the end of 2012 he will be 69.
As governor of liberal Minnesota, Pawlenty has a record of winning over moderates, but will struggle to compete with Palin for the religious right.
A relative unknown, he won a straw poll among 'values voters' this week, but still remains an outside shot. Leo Hornak