WASHINGTON – In a boost for the president on global warming, the Senate on Thursday rejected a challenge to Obama administration rules aimed at cutting greenhouse gas emissions from power plants and other big polluters.

The defeated resolution would have denied the Environmental Protection Agency the authority to move ahead with the rules, crafted under the federal Clean Air Act.

With President Barack Obama’s broader clean energy legislation struggling to gain a foothold in the Senate, the vote took on greater significance as a signal of where lawmakers stand on dealing with climate change.

“If ever there was a vote to find out whose side you are on, this is it,” said Sen. Barbara Boxer, D-Calif., chairman of the Environment and Public Works Committee.

The vote was 53-47 to stop the Senate from moving forward on the Republican-led effort to restrain the EPA.

Maine Republican Sens. Olympia Snowe and Susan Collins supported the losing effort.