Republican leaders in the House and Senate said Wednesday that they will reject Democratic demands for an immediate extension of health care subsidies, challenging Democrats to vote against a stopgap spending bill that doesn't include them but will keep the government open at the end of the month. Senate Majority Leader John Thune, R-S.D., said Democrats “have a choice to make” as the Sept. 30 deadline approaches. Democratic leaders have so far shown no signs of backing off their demands, arguing that it’s Republicans’ responsibility to negotiate with them as they will need at least seven Democratic senators to move the stopgap spending bill forward.