SAN FRANCISCO, Calif. — Major changes to the way people vote has election advocates on edge as Californians cast ballots in the Democratic presidential contest and other primary races.

The “Super Tuesday” primary in the country's most populous state comes amid changes aimed at expanding voter participation, including new voting equipment and vote centers that are replacing polling places in some counties. Those changes may confuse some people.

There are fears California might end up with a mess much worse than Iowa, where the Democratic Party couldn't declare a winner for several days.

Advocates say voters are hanging onto their ballots, which will likely mean long lines Tuesday.