House Speaker Dennis Hastert, whose words influence Illinois Republicans, said Thursday that Steve Rauschenberger is the best candidate to replace Jack Ryan, who abandoned his bid for the Senate over lurid sex allegations.

Party leaders are expected to name a candidate next week, and Rauschenberger, a state senator who finished third to Ryan in the March primary, is one of a number of Republicans who have submitted applications to the GOP State Central Committee for consideration.

"My perspective is, if he runs and lays out Republican principles and runs a good campaign, he's helping a lot of Republicans," Hastert told The Associated Press.

Rauschenberger, at the state Capitol Thursday for a special session on the budget, said he was flattered by Hastert's comments and the party's interest. But he said he was still studying the situation and had not decided whether he wants the nomination.

The race would be a challenge for any Republican candidate, who would have to start less than four months before the election and raise millions of dollars to run a competitive campaign against Democrat Barack Obama.

Asked about fund-raising concerns, Hastert said: "If he makes that decision, we'll do everything we can to help him."

Obama, also a state senator, already has a strong campaign war chest in his bid to replace retiring GOP Sen. Peter Fitzgerald. Obama's campaign announced on Tuesday that it had raised $4 million in the last three months, an almost unheard of amount for an Illinois Senate race.

Ryan, a millionaire investment banker turned teacher who won the GOP Senate primary in March, dropped out of the race two weeks ago after a judge opened records from his 1999 divorce from actress Jeri Ryan. In them, Jeri Ryan contended Ryan took her to sex clubs and tried to pressure her to perform sex acts in front of others. He has denied the allegations.