Massachusetts may account for about 2 percent of the nation's population, but when it comes to nurturing White House dreams, the Bay State is a political boomtown.

Since 1960, at least half a dozen Massachusetts politicians have launched serious campaigns for president, while a handful of others have toyed with the idea.

Three captured their political party's nomination and one, John F. Kennedy, went on to occupy the office.

The difference this election cycle is that the politician aiming to be the fourth major party nominee from Massachusetts in the past five decades, Mitt Romney, is a Republican.

"You can say that all governors and senators see themselves as potential presidential contenders," said Boston College political science professor Marc Landy. "What's perhaps more surprising is how successful Massachusetts politicians have been in making themselves very serious contenders."

What makes the streak even more unusual is Massachusetts' reputation as one of the most liberal states in the country.