WASHINGTON (AP) ― The Senate killed Republican-backed attempts to overturn several of President Barack Obama’s environmental and energy policies Thursday as lawmakers worked against a March 31 deadline to keep aid flowing to more than 100,000 transportation construction projects around the country.

The two-year, $109 billion transportation bill before the Senate has wide, bipartisan support, but has become a magnet for lawmakers’ favorite causes and partisan gamesmanship. Among the amendments batted aside were GOP proposals to bypass Obama’s concerns about the Keystone XL oil pipeline, to delay tougher air pollution standards for industrial boilers and to expand offshore oil drilling.

Action on those and other amendments came under an agreement between Senate Majority Leader Harry Reid, D-Nevada, and Minority Leader Mitch McConnell, R-Kentucky, aimed at clearing the way for passage of the transportation bill next week.