Carter Aides Concede to Senators That $50 Tax Rebate Is in Trouble
High Adm officials privately express fear that Carter's tax rebate plan is in trouble in Sen because of ideological differences and pol resentments; Mondale and Blumenthal confirm fear, meeting; basis of opposition by some Dem and Repub Sens noted; Long and other powerful Sens have not used their persuasive powers on behalf of Carter; Repr Philip Burton tells Carter there is theory on Capitol Hill that White House seeks confrontation with Cong; says Carter denies it; Jody Powell says rebate dispute is partisan issue; 38 Repubs, Harry F Byrd (ind) and Dem Floyd Haskell reptdly oppose rebate; position of some other Sens noted; some comment (M)
