President Obama looks on as former president Bill Clinton speaks in the briefing room of the White House in Washington in 2010. (J. Scott Applewhite/AP)

The event was put together by McAuliffe, a businessman, former chairman of the Democratic National Committee and probable gubernatorial nominee next year. It will be held April 29, sources say.

The presidents’ appearance in Virginia speaks to the importance of the swing state in both the presidential and U.S. Senate races in November.

Virginia is considered crucial to Obama winning reelection and Democrats retaining control of the U.S. Senate. (Obama’s friend, former governor Tim Kaine, will face the winner of the Republican primary, most likely former senator George Allen).

McAuliffe, a nationally known political celebrity who calls Bill and Hillary Clinton close friends and appears on Sunday morning talk shows, has worked in national politics for almost three decades. He raised more than $200 million for Bill Clinton in the 1990s and chaired Hillary Clinton’s presidential campaign, which raised about $220 million.

In 2008, Obama became the first Democratic candidate to carry Virginia in 44 years, but in the years since, Democrats have lost ground. The GOP now controls all of Richmond and constitutes a majority of Virginia’s congressional delegation.

Obama and Sen. John McCain (R-Ariz.) fiercely courted Virginia’s 13 electoral votes three years ago, giving the state a front-row seat to a presidential election for the first time in decades. Both candidates, as well as numerous surrogates, made repeated visits to the state and flooded airwaves and mailboxes with advertisements.

Obama’s win was attributed to a highly developed ground game and an energized base of supporters who gave him an advantage in the get-out-the vote effort.

In what was then considered the most comprehensive political organization in modern times, Obama opened almost 50 offices, even in sparsely populated regions, dispatched more than 250 paid staffers and recruited thousands of volunteers to knock on doors across the state.

In Virginia’s closely watched U.S. Senate race, likely nominees Allen and Kaine remained tied, as they have been in many previous polls. Eight months before Election Day, Allen received support from 44 percent of those questioned, while Kaine received the backing of 47 percent.

The race, which will fill the seat of retiring Sen. Jim Webb (D), is expected to be one of the most competitive in the nation, and could help determine which party controls the U.S. Senate.

Clinton headlined a fundraiser for the Senate Democratic caucus at McAuliffe’s home last year as Republicans aggressively fought to take control of the Senate.

During McAuliffe’s run for governor in 2009, Clinton spoke at a rally for him. He also made a surprise appearance at a New York fundraiser for McAuliffe and was the keynote speaker at the state party’s annual Jefferson-Jackson dinner.

As pretty much every observer of Virginia politics knows, McAuliffe, 54, is eyeing a second run for governor in 2013.

McAuliffe — who also is working to reopen a shuttered paper mill and launch an electric car venture — has been helping Democratic candidates in Virginia whenever he can as he looks to overcome complaints from 2009 that he hadn’t paid his dues in state politics.

McAuliffe has spoken to Gov. Bob McDonnell and Lt. Bill Bolling, the chief jobs creation officer, several times in recent weeks about opening a car plant in Virginia.

McAuliffe, chairman of GreenTech Auto, paid $20 million in May for Hong Kong-based EuAuto Technology, which builds an electric vehicle called the MyCar. He secured a package of incentives from then-Mississippi Gov. Haley Barbour (R) to build a facility in that state, which is now in operation.

Sen. Chap Petersen (D-Fairfax), who announced the creation of a leadership PAC earlier, is likely to run for governor against McAuliffe.

Follow me on Twitter: anitakumar01