A fresh clash brewed Thursday between Hillary Clinton and Barack Obama over proposals to redo Florida's voided primary which could weigh heavily on the outcome of their White House brawl.
The campaigns jostled for position after Democratic leaders in the southern state released a blueprint for a postal primary, with a voting deadline of June 3.
The fierce rivals meanwhile both appeared in the Senate for votes, and in an intriguing encounter held a private and intense conversation which lasted for several minutes.
Later, Obama's campaign said he had agreed to debate Clinton twice before their next voting showdown, the Pennsylvania primary on April 22. The former first lady's camp is yet to confirm she will join the second encounter.
Both Florida and Michigan had their delegations to August's Democratic convention stripped after leapfrogging other states by holding primaries before "Super Tuesday" on February 5, in defiance of party rules.
Candidates largely stuck to a pledge not to campaign in the two states, but Democratic bosses fear they could alienate millions of general election voters by throwing out their primary ballots.
The Clinton camp said it preferred that nominating delegates be apportioned on the basis of the original vote -- a formula that would give Clinton a clear advantage -- but were open to other options.
"Our preference ... is to honor the elections that have already taken place in Florida as well as in Michigan," said campaign deputy communications chief Phil Singer.
"If that's not possible we believe there should be a redo of the vote."
Obama surrogates pushed back against the idea of a revote, and questioned whether a primary by mail was feasible, secure or fair.
Florida congressman Robert Wexler, who backs the Illinois senator, told Fox News that a new vote would be a "recipe for chaos."
"We will have two contested elections, rather than one."
Obama was meanwhile quoted by CBS News as saying that another proposal, to simply dole out the delegates on the basis of the original votes, "defies logic." He was not on the ballot in Michigan.
Florida Democratic chiefs outlined the plans in a memo to the presidential campaigns and national party leaders, arguing it was the only realistic way out of a convention nightmare.
"We have reexamined every potential alternative again. Only one stands out as fair, open, practical and feasible at this time," said the memo.
"We are positive that a combination vote-by-mail and in-person election can be conducted in the time available," it said.
The status of Florida and Michigan is crucial to the former first lady, as she seeks to cut Obama's current lead of around 120 nominating delegates.
She won the original Florida contest, in which 1.75 million votes were cast, by 50 to 33 percent. So Clinton would be favored to claim most of the state's 210 nominating delegates in a repeat primary.
Democrats in Michigan, where Clinton's was the only name on the ballot, are also considering plans for a repeat primary.
Even if the Florida and Michigan delegates are restored, neither Clinton nor Obama looks likely to reach the finish line of 2,025 delegates needed to capture the nomination.
That will leave the party's presidential nomination in the hands of "superdelegates," nearly 800 top party officials and lawmakers who can vote how they like at the convention.
The Democrats were still caught in the fallout of their latest racially tinged clashes, which prompted party heroine Geraldine Ferraro to step down as a member of Clinton's finance committee on Wednesday.
Ferraro had suggested that Obama had an advantage because he was black, sparking a tirade of charges and counter-charges between the two campaigns.
Addressing a largely African-American audience in Washington Wednesday night, Clinton pointedly apologized if some of her campaign's tactics had insulted black Democrats.
"I am sorry if anyone was offended. It was certainly not meant in any way to be offensive," she said, referring to remarks by her husband, ex-president Bill Clinton, who had likened Obama's campaign to civil rights leader Jesse Jackson's unsuccessful presidential efforts.
Obama's camp said the two televised debates would take place on April 16 in Philadelphia, and April 19 in North Carolina.
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