Sean Spicer declines to slam the door on carbon tax

White House press secretary Sean Spicer refused to rule out consideration of a carbon tax when asked about the idea at Tuesday's White House briefing:

There's a robust debate going on with respect to comprehensive tax reform … I'm not going to comment on specific prongs of that.

Why it matters: It's a bit puzzling that the White House is not flatly slamming the door, because a carbon tax has almost no buy in or political traction among influential Republicans. It's at least the second time Spicer has declined to rule it out.

• A spokesman for Senate Majority leader Mitch McConnell reaffirmed Tuesday that he has "long been an opponent of an energy tax." Groups such as Heritage Action and the Koch-backed Americans for Prosperity are strongly opposed.

Flashback: In early February Republican elders from the Bush presidencies and the Reagan era—including James Baker, Hank Paulson and George Shultz—pitched a plan to tax emissions, return the money to the public, and scuttle climate regulations.

• In February Baker and some other backers met with senior White House officials including top economic adviser Gary Cohn and chief of staff Reince Priebus. Spicer batted aside questions about it at the time without ruling it out then either.