(CNN) -- Americans set a record for number of votes cast in this presidential election but failed to make history with the percentage of voter turnout, experts said. A record 2.9 million voters cast ballots Tuesday in Missouri. Curtis Gans, director of American University's Center for the Study of the American Electorate, said Thursday that percentage turnout was lower because Republicans stayed away from the polls. Disappointment over Sen. John McCain's choice of Alaska Gov. Sarah Palin as his running mate, combined with a perception that the ticket would lose, prompted many would-be Republican voters to ditch the polls on Election Day, Gans said.
@highlight
Report: About 127 million votes cast, shattering 2004 record
@highlight
Turnout percentage about 61 percent, compared with 1960's 67 percent
@highlight
Early voting tracker: 31.7 million voted early in at least 30 early voting states
@highlight
Another expert's estimate projects nearly 131 million Americans voted
"There was real hostility ... amongst moderate Republicans" that @placeholder would choose the conservative governor, Gans said.