Story highlights Over 450,000 Americans had already voted

States where a majority of ballots are cast early already include Florida, Nevada, North Carolina and Colorado

(CNN) More than 450,000 Americans had locked in their votes for president before Hillary Clinton and Donald Trump met on stage for a contentious debate Sunday night, and even before the revelation of a video where Trump can be heard making sexually aggressive and lewd remarks about women, according to early vote returns from across the United States.

In 27 states where data have been made available so far, early votes have been cast or absentee ballots returned by at least 455,878 people. In most of those states, the data cover a period through Thursday, the day before news broke of the 2005 video of Trump, others cover a period ending earlier, and no state total can reflect ballots that had been mailed but not yet received or tallied by election officials, meaning the total number of votes cast before Friday's campaign-altering news is likely greater.

The available data includes results from nine states where some recent polls have found a tight race between Clinton and Trump that will be critical to the outcome of the presidential election -- Florida, Nevada, North Carolina, Ohio, Michigan, Iowa, Colorado, Wisconsin and Virginia. Those states make up a significant share of the votes cast so far, with about 190,000 total returned ballots or early votes coming from those nine.

Iowa, which has tilted Trump in most polling so far, leads the way, with more than 77,000 votes cast, Wisconsin, more of a Clinton stronghold based on polling there, follows with 76,559. Both states are among those where election experts expect a significant share of the vote to be completed before Election Day.

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