(CNN) - What a difference a year makes.
Last summer the White House enlisted former President Bill Clinton to help in trying to convince Rep. Joe Sestak to not mount a Democratic primary challenge to Sen. Arlen Specter of Pennsylvania, who had just switched from the Republican to the Democratic party.
Fast forward to the summer of 2010 and Sestak is the party's Senate nominee and Clinton will now head to Pennsylvania to campaign with the former Navy admiral.
Sestak's campaign announced Wednesday that Clinton will headline a Sestak rally in Scranton, Pennsylvania next Tuesday afternoon. The same day Clinton is scheduled to be the main attraction at a fundraiser for Bethlehem Mayor John Callahan, the Democratic nominee in the state's 15th congressional district. Callahan faces off against incumbent GOP Rep. Charlie Dent in November.
The former president is also headed to Florida later this month, to campaign for Rep. Kendrick Meek's bid for the state's Democratic Senate nomination. Meek, a four-term lawmaker who represents Florida's 17th congressional district in the southeast part of the state, faces off August 24 against billionaire real estate investor Jeff Greene in the Democratic primary.
The winner will battle former Florida House speaker Marco Rubio, the likely Republican nominee, and Republican Florida Gov. Charlie Crist, who is now running for the Senate as an independent candidate, after dropping out of a battle with Rubio for the GOP nomination. Most recent polls indicate that Crist has a narrow lead over Rubio, with either Meek or Green a distant third.
Last month CNN learned that President Obama's aides are putting together an aggressive schedule to deploy Clinton at campaign and fundraising events in key states around the country in the weeks ahead. According to Democratic officials familiar with the plans, the White House specifically wants to use Clinton in key swing states where Obama is not particularly popular, such as Arkansas and Kentucky.
Earlier this year, Clinton went back to his home state of Arkansas to help Sen. Blanche Lincoln win a bruising primary runoff election against the state's lieutenant governor. Lincoln now faces a very tough re-election battle in November against Republican Rep. John Boozman.
Clinton will also be used in Kentucky, where Democrats would love to pick up an open seat now held by the retiring Republican Sen. Jim Bunning. Kentucky Attorney General Jack Conway, the Democratic nominee, faces off in the general election against Republican nominee Rand Paul, a favorite of many in the Tea Party movement.
Clinton also hit the campaign trail in June, when he teamed up with Mark Critz, the Democratic candidate in the special election to fill the late Democratic Rep. John Murtha's Pennsylvania seat. Critz ended up defeating Republican candidate Tim Burns.
The two-term Sestak served as director for defense policy on the National Security Council under Clinton. Two months ago White House Counsel Bob Bauer released a memorandum revealing that White House Chief of Staff Rahm Emanuel had enlisted Clinton's help to offer Sestak an unpaid position on a presidential advisory board. But Bauer concluded there was no wrong doing by the White House, saying that "allegations of improper conduct rest on factual errors and lack a basis in the law."
The developments came on the same day that House Republicans demanded the White House turn over internal documents related to what they call a failed effort last year to try and persuade Sestak to forgo a primary challenge to Specter, in exchange for a government job.
Sestak ended up announcing his Senate bid last August. He defeated Specter in Pennsylvania's May 18 primary. He faces off in November against former Rep. Joe Toomey, the GOP nominee. A Quinnipiac University poll of Pennsylvania voters conducted last month indicated the race is dead even.