The Iowa caucuses haven't yet happened, but millions of Americans are already free to vote.
Many of the Super Tuesday states that hold primaries on March 3 offer early voting. That gives campaigns a chance to bank votes before results in the first four voting contests can reshape the trajectory of the race.
Early voting began in person last week in Minnesota. California, Colorado, North Carolina and Texas are expected to see a strong early voting turnout, either by mail or in person, when it opens next month.
Many of the 14 Super Tuesday states will offer some form of early voting between now and mid-February, according to The Associated Press.
Because of this, Democratic candidates are having to focus not only on the first four contests in Iowa, New Hampshire, Nevada, South Carolina and Nevada, they also have to reach out to early voters in the Super Tuesday states.
Two candidates don't have this problem. One is billionaire Michael Bloomberg, who is ignoring the first four states entirely and focusing on an advertising blitz for Super Tuesday.
The other is President Donald Trump, who isn't facing a serious threat to be the Republican nominee again. Although he has a couple of long-shot challengers, some state Republican parties have already chosen to skip their primaries and give Trump their delegates by default.