It's the day California and many other states will hold primaries that are likely to decide the final candidates.
The California primary is still a month away but that doesn't mean you have to wait to vote.
Absentee ballots are available as soon as Monday and the early voting could have a big impact on the outcome.
Unlike the Iowa caucuses, where only a few voters pick the winners, in the California primary all registered voters will have a say. Political Science Professor Ken Friesen believes their votes are expected to make a real difference.
"The more the polls are showing this to be a statistical dead heat, the more important role California is going to be playing."
Fresno County Clerk Victor Salazar is expecting a voter turnout of at least 70 percent.
"Our sense is that voters will turn out in this election. It's very competitive within the parties."
Ken Friesen says what happens in Iowa and New Hampshire may well be overshadowed by the California primary and the voters of 21 other states who cast ballots on February fifth.
"There are certainly other primaries but when you have 22 states voting on a single day, that is obviously a very important day. So early February will be really the key I think. From there on, unless it's still very close, I think that will basically determine the election in terms of the primaries."
The growing number of independent voters could also be a big factor.
In Fresno County for example, republicans outnumber democrats by 17-k.
But there are nearly 44-k voters who decline to state a party preference. Republicans won't allow any of those independents to vote in the primary but democrats welcome their votes.
"The fact there's a lot of independents in California, especially young independents and those tend to be looking more to Obama, potentially Obama supporters and so I think that will play a role."
California voters don't have to wait until February fifth to vote in the primary.
Mail in ballots can be accepted as soon as this coming Monday. And in Fresno County more voters vote by mail than at the polling place.