‘Idols’ Simonized Seattle Seahawks running back Shawn Alexander was so touched by last Wednes day’s “American Idol: Idol Gives Back” fundraising ef fort that he’s writing a check for $50,000 to the involved charities. Alexander is a regu lar “Idol” viewer.

I don’t know who Alexander thinks will win this season’s competition but – no surprise here – “Idol” judge Simon Cowell has a definite opinion.

“I think the front- runners at the mo ment I would say are Jordin [Sparks] and Me linda [Doo little],” Cowell tells Ellen DeGen eres on her show today (4 p.m./Ch. 4). “That’s my gut feeling, although I wouldn’t write off Blake [Lewis] or LaKisha [Jones].”

Elsewhere in talk-show land, Judy Sheindlin (“Judge Judy”) visits tomorrow’s “Ra chael Ray Show” (10 a.m./ Ch. 7) with three of her granddaughters, Jenna, Sara Rose and Emma – who joined Judy and Rachael Ray at Mariani Gardens in Arm onk to make floral arrange ments for Mother’s Day.

And, over on the radio talk- show side, Alison Stewart, late of NBC/MSNBC, has joined NPR. She and Luke Burbank will host a show starting in September.

MSNBC, by the way, scored big numbers last Thursday night with its coverage of the Democratic Candidates De bate – a winning 2.3 million viewers (7-8:30 p.m.).

Last, but not least: * Michael J. Fox makes the introductory remarks Thursday at the New York Stem Cell Foundation-spon sored panel (92nd St. Y).

* May 8: Deborah Norville (“Inside Edition”) hosts the Annual Girl Scout Council of Greater New York Tribute Dinner, featuring Amy Seda ris.