NICE TRY: It seemed like a good idea at the time. . . . House Democratic leaders thought they saw a way to direct up to $3 billion in extra defense money to social programs in the wake of the L.A. riots. The programs could have been part of the Pentagon spending bill if they were linked to the nation's conversion to a post-Cold War economy. But the congressional and White House arbiters of an accord that prevents the shifting of funds from one part of the budget to another aren't buying it. Now, House Armed Services Committee Chairman Les Aspin (D-Wis.) will propose that the $3 billion be used to trim the budget deficit.