CHICAGO – Illinois Gov. Rod Blagojevich on Wednesday signed a law moving up the state’s primary election to Feb. 5, helping hometown favorite Barack Obama.

As many as 25 states could hold primaries that day, with at least 1,370 delegates at stake.

“Illinois is the fifth largest state in the country. The people who live here deserve to play a bigger role in deciding who the presidential candidates will be,” Gov. Rod Blagojevich said in a written statement.

The state’s primary would have been March 18. Nominees often have been decided by the time Illinois’ primary is held.

The state’s Democratic Party chairman, Illinois House Speaker Michael Madigan, proposed moving up the primary so Obama, a first-term senator from Illinois, could count on an early victory in a big state.

“While the move is not something he actively lobbied for, Barack Obama welcomes the opportunity for his home state to play a role in the nominating process and he is grateful for the base of support he has from friends, family and supporters in Illinois,” Obama spokeswoman Jen Psaki said in a written statement.

Obama is a top contender in a crowded Democratic field for his party’s nomination. His rivals include former first lady and New York Sen. Hillary Rodham Clinton and former vice presidential nominee John Edwards.