At this point, Republicans do not have the votes to repeal the E.P.A. regulations, which will have far more impact on curbing carbon emissions than stopping the [Keystone] pipeline, but they say they will use their new powers to delay, defund and otherwise undermine them. Senator James M. Inhofe of Oklahoma, a prominent skeptic of climate change and the presumed new chairman of the Senate Environment and Public Works Committee, is expected to open investigations into the E.P.A., call for cuts in its funding and delay the regulations as long as possible. [...] Mr. McConnell signaled last week that he, too, wanted to cut the E.P.A.'s budget to keep it from enforcing environmental regulations. Republicans might also include provisions that would repeal the E.P.A. regulations in crucial spending bills -- a tactic that could force a standoff between Mr. Obama and Mr. McConnell over funding the government.
Republicans have spent six years campaigning against President Barack Obama's "war on coal" and promising to fight the Environmental Protection Agency's regulations. Now that Republicans have gained control of both chambers of Congress, they are in a position to declare war with the EPA.