Democrats Block Stock-Trading Bill, Denying the G.O.P. a Pre-Midterm Win

A Republican measure to limit, but not bar, congressional stock trading faltered in the Senate as Democrats thwarted a G.O.P. bid to show progress on an issue that has rankled voters.Stock trading by members of Congress has become a politically toxic issue for both parties, one that they are trying to use against each other in competitive midterm races.