Senate Democrats voted Thursday to block a motion to advance a House-passed bill to fund the Department of Homeland Security, putting Washington on the brink of a partial government shutdown that will affect more than 260,000 federal employees.The motion, which required 60 votes, failed to advance by a vote of 52-47.Centrist Sen. John Fetterman (D-Pa.), who has a long-standing policy of voting against government shutdowns, was the only Democrat to vote for advancing the measure.Senate Majority Leader John Thune (R-S.D.) voted no for procedural reasons to be able to bring the bill back to the floor quickly at a later...