Illinois State Senator Kirk Dillard's phone is ringing off the hook these days, and not in a good way. Mr. Dilliard is a Republican, and until April he was the chairman of the DuPage County GOP, one of the party's strongest political organizations in the state. That's why many were surprised to see Mr. Dillard featured prominently in a new television ad praising Senator Barack Obama.

"Sen. Obama worked on some of the deepest issues we had and was successful in a bipartisan way," Mr. Dillard says in the ad, which began airing in Iowa this week. "Republican legislators respected Sen. Obama. His negotiation skills and an ability to understand both sides would serve the country very well."

Mr. Dillard's friendship with Mr. Obama is well known, but some Illinois Republicans are questioning whether Mr. Dillard went too far in taking such a prominent role promoting Mr. Obama's candidacy.

Frank Watson, the Republican leader in the Illinois state Senate, says Mr. Dillard "is a leader in the Republican Party, and I think maybe that's a step beyond where he should have gone." Others have been less kind, calling Mr. Dillard's appearance in the Obama ad a ploy for publicity and "a disgrace." Former Republican Senate President James "Pate" Philip summed up his feelings about Mr. Dillard's actions this way: "To say I was disappointed in him would be an understatement."

Mr. Dillard doesn't understand what all the fuss is about, nor does he appear to appreciate the criticism, blaming the flurry of calls to his office on "ultra-right committeemen" and "agitators out there who spanked these guys into a frenzy."

Mr. Dillard says he remains a "Republican stalwart" who is backing Arizona Senator John McCain for President. But in language reminiscent of the kind that has often gotten the original Maverick into trouble with his party, Mr. Dillard told the Chicago Tribune: "My caucus should thank me for the last 48 hours of media attention, whether they realize it or not."