The Illinois Republican Party scrambles to find a candidate to pit against Barack Obama in the wake of Jack Ryan's quitting the Senate race: Beleaguered Republican U.S. Senate hopeful Jack Ryan ended his campaign Friday, leaving his party scrambling to find a replacement with enough money and magnetism to mount a serious challenge against Democratic candidate Barack Obama. Ryan had been under attack by a wide range of party leaders for a lack of candor following the release this week of previously sealed records from his divorce from TV actress Jeri Ryan, giving rise to what one prominent Republican called "buyer's remorse." Jack Ryan had fought the release, insisting he was trying only to protect his son and not to hide embarrassing information. But the files showed Jeri Ryan had accused her ex-husband of taking her to sex clubs and trying to pressure her into having sex in front of others. Ryan met with staff Friday morning to inform them of his decision to quit the race. Later, he issued a statement explaining he was stepping down because a fixation on the divorce charges meant that a "debate between competing visions and philosophies" could not take place in the Senate race. ...Republican pressure on Ryan to step aside began Monday with the release of the files, including one document in which Ryan vigorously denied the allegations of his ex-wife. Los Angeles Superior Court Judge Robert Schnider released the information as the result of motions filed by the Chicago Tribune and WLS-Ch. 7. Calls for Ryan's withdrawal intensified throughout the week as party officials--saying Ryan misled them about the extent of his ex-wife's allegations--warned of the damage he could do to an already struggling party's chances in November. On Thursday, U.S. House Speaker Dennis Hastert of Plano and state GOP chairwoman Judy Baar Topinka called U.S. Sen. George Allen, chairman of the National Republican Senatorial Committee. They asked him to pull the plug on Ryan's campaign, according to a GOP source who spoke frequently with top Ryan campaign staffers...Even before the release of the court files, Ryan had trailed Obama by a wide margin in public opinion polls, and his decision to quit came after his campaign commissioned yet another poll to gauge public response to the growing divorce file controversy, the Republican source said.