President Clinton, who hopes to jump-start hiswelfare reformeffort with a 5 1/2-hour bipartisan summit Saturday, today cautioned the GOP against trying to cut off benefits to people "without regard to what will happen to their children." But eager Republicans, especially House freshmen, warned in return that Clinton would have to jump to their tune. "I think the train is way down the track on welfare and that the president is jumping on the caboose. But I'm happy to have him on board," said Rep. Tim Hutchinson (R-Ark.), who will attend the high-level meeting of Congress members and governors.TIME Washington correspondent Ann Blackmansays Clinton staffers are promising no proposals from the meeting. Instead, she says, Clinton will probably point to the summit later to claim bipartisan support for the two sides' common goals: a work requirement, making deadbeat dads pay child support anddiscouraging teen pregnancy.