With President Barack Obama likely facing a tough battle in November, speculation continues to build that he’ll dump Joe Biden as his running mate and replace him with a more popular Democrat -- namely Hillary Clinton. But history shows that replacing the vice president does little for an incumbent president and some experts are betting that the “O and Joe” pairing will once again top the Democratic ticket.

One man with inside knowledge on movements to dump the vice president expects a similar campaign against Biden later this year -- but expects Obama to keep his running mate in place. Back in 1992, pointing to the gaffes the vice president had committed, prominent Republicans called on then-President George H.W. Bush to drop Dan Quayle from the Republican ticket and replace him with someone more palatable to the general public, such as Jack Kemp. Despite the pressure, Bush kept Quayle.

Speaking to John Miller at National Review, Quayle thinks that there will be calls to dump Biden but insists that Obama will keep him on the ticket.

“There will be a push to drop him, but it won’t happen,” Quayle told Miller. “Why switch? Putting someone else on the ticket won’t help. The president must get re-elected on his own. Changing the vice presidential candidate would create too much discord and chaos.”

One Republican who wanted Quayle off the ticket in 1992 was former President Gerald Ford. Ford was the last president who tossed aside his vice president and it didn't work out for him. Neither the president, who was appointed vice president by Richard Nixon before taking over the White House in 1974, nor his vice president, Nelson Rockefeller, had been elected to their offices when Ford turned his attention to winning a term in his own right in the 1976 election cycle.

Ford decided Rockefeller, a veteran of New York and national politics who was much more liberal than most Republicans, was a liability, and replaced him with a rising political star from Kansas by the name of Bob Dole. Despite being dumped, Rockefeller helped Ford by delivering New York to the president during his close contest with Ronald Reagan for the Republican nomination.

Ford went on to lose to Democrat Jimmy Carter in a close contest that November. Carter carried New York by 4 points over Ford -- enough of a margin to think that Rockefeller, who had carried the Empire State four times in gubernatorial elections, could have helped turned the tide for the Republicans.

While Ford would later muse that removing Rockefeller from the 1976 Republican ticket was one of his chief regrets as president, he urged two later presidents to do the exact same thing. In “Write It When I'm Gone,” a book of conversations he had with Ford, Thomas M. DeFrank recounts that the former president urged Bush to dump Quayle from the 1992 ticket and later urged George W. Bush to replace Dick Cheney, who had been White House chief of staff under Ford, with either Rudy Giuliani or George Pataki in 2004.

With the exceptions of Ford dumping Rockefeller and FDR replacing John Nance Garner with Henry Wallace -- and then tossing aside Wallace for Harry Truman four years later -- most presidents of the last century seemed content keeping their vice president on the ticket, though there were signs that, had he survived to run again in 1924, Warren G. Harding would have replaced Calvin Coolidge with Charles Dawes (who, ironically, would serve an unhappy stint as Coolidge’s vice president after Harding died in 1923).