The White House is promising Senate Democrats it will do all it can to hold John Kerry’s seat in Massachusetts, which Democrats fear may be lost to just-ousted Republican Scott Brown.

President Barack Obama, first lady Michelle Obama and former President Bill Clinton will all campaign for the Democratic candidate to replace Kerry, who is being nominated for secretary of state, a Democratic official tells Politico.

Even Secretary of State Hillary Clinton, whom Kerry is expected to be confirmed easily to replace, might get involved.

“The [Democratic Senatorial Campaign Committee] and Senate Democratic leaders have received assurances that the White House will be all in,” a party official told Politico, speaking on condition of anonymity. “The president, the first lady, President Clinton and possibly Secretary Clinton will all campaign in state and fundraise to support the Democratic nominee.”

The promise of financial and political help from the Obamas and Clintons will help allay the fears of Senate Majority Leader Harry Reid, D-Nev., and other top Democrats that Kerry’s departure puts a safe Senate seat in play. Brown, who lost his seat to consumer advocate Elizabeth Warren but remains popular, is considered likely to run. And polls show him leading likely Democrats.

Obama, however, swept Massachusetts in the presidential election over the state’s former governor, Mitt Romney.

The president officially nominated Kerry, the 2004 presidential candidate, on Friday to succeed Clinton. A special election will take place within 145 to 160 days of Kerry’s resignation. This sets up a likely mid- to late-June election, with the party primaries in late April or early May.

Democratic Gov. Deval Patrick will appoint a caretaker to occupy the seat after Kerry resigns and until voters choose a successor in the election. Patrick, who says he will not run himself, has spoken with Vicki Kennedy — widow of the late Sen. Ted Kennedy — about the interim appointment, the Boston Globe reports. Michael Dukakis, the former governor and 1988 presidential candidate, and retiring Rep. Barney Frank also have been mentioned.

Potential candidates for the Democratic nomination in the special election include Reps. Ed Markey, Mike Capuano and Stephen Lynch. Edward Kennedy Jr., the son of the late senator, and actor Ben Affleck also have been mentioned as possible candidates.

Kennedy is an advocate for the disabled and co-founder of the New York-based Marwood Group, which calls itself "a health care-focused strategic advisory and financial services firm."

Brown is almost certain to be the Republican nominee. A WBUR poll released this week showed him leading a generic Democratic candidate by eight points, and he trounced Markey, Capuano and Lynch in head-to-head matchups. Democrats, though, have an overwhelming voter registration advantage in Massachusetts, and they are confident Brown’s lead would wither in the face of an actual campaign.

Brown made it clear he was available in his farewell address on the Senate floor, declaring that both victory and defeat are "temporary" things, the Associated Press reported. "Depending on what happens, and where we go, all of us, we may obviously meet again."

He retains a statewide political organization and more than $400,000 left in his campaign account.

In the unlikely event he doesn’t run, former Gov. William Weld, former gubernatorial candidate Charles Baker and Richard Tisei, who just lost a narrow race to Rep. John Tierney, D-Mass., are Republicans waiting in the wings, the AP reports.

Whoever wins the special election will have to defend the seat again in 2014. Patrick has pledged to fill out his second term, but could run in that election.

The Brown-Warren race this year was the most expensive in Bay State history, Politico notes, with the two candidates raising and spending $70 million themselves, in addition to millions of dollars in TV ads by outside groups and super PACs.

Massachusetts voters are not looking forward to yet another Senate race, The Boston Globe reports.

This constant contest is highly unusual in Massachusetts, where Kennedy claimed one Senate seat for nearly 47 years and Kerry held the other for 27.

“We’ve had such longevity for such a long period of time and a lack of really competitive races,” Peter Ubertaccio, director of the Martin Institute at Stonehill College, told the Globe.

Suddenly, he said, Massachusetts could be “overdosing on Senate races.”

“I really think there is a sense that people are fatigued by politics,” Ubertaccio said.

So were voters interviewed at Boston’s South Station by the Globe Friday. “I’m not looking forward to the politicking and all the ads,” said Pam McCarron, 72, of Boston. “They just had the election.”

Edson Silva, 22, a tax associate who lives in Brockton, also worried about the barrage of advertising.

“I don’t know if I can really handle another spate of campaign ads,” said Silva. “I feel like there should be a limitation on how many ads you can put out. It’s outrageous.”

“It was getting very trying,” 72-year-old Joan Phelan agreed. “All the phone calls, all the literature. I’m glad that’s over.”