In the 1984 election, the then-Colorado senator shocked the political establishment when he beat former Vice President Walter Mondale by 10 percentage points in the New Hampshire primary.

NPR: Beyond Iowa: Bounce or Bust?

Dean stunned the Democratic establishment last month when he won the backing of former Vice President Al Gore.

CNN: Bradley endorses Dean

He spent the next few months campaigning as much against Kennedy as he did against Vice President Hubert Humphrey, who became the choice of the party establishment after Johnson's withdrawal.

NPR: Remembering Eugene McCarthy

Most of Washington's Democratic establishment, including popular Gov. Gary Locke, favors the vice president.

CNN: Gore campaign bites back

Washington (CNN) -- Although Rage thinks Paul Ryan is just another cog in the "Machine, " that doesn't stop the Republican vice presidential hopeful from rocking out to the rap metal group's anti-establishment lyrics.

CNN: Ryan Rages Against the Machine

"The more the establishment tries to force (Santorum) out of the race, the stronger his argument is with the grass-roots that the establishment is ganging up on him and being unfair, " said Darrell West, vice president and director of governance studies at the Brookings Institution.

CNN: Santorum benefits from staying in GOP race