State Rep. Daryl Metcalfe can't seem to help himself when it comes to embarrassing his long-suffering constituents in southern Butler County. Long known for intemperate comments that he sometimes has to provide "context" for later, Mr. Metcalfe has distinguished himself more as a gaffe machine than an effective leader.

Instead of insulting Muslims or homosexuals this time around, the Cranberry Republican had in his crosshairs a group of veterans who are traveling the country to raise awareness about climate change. During the Pennsylvania leg of a 21-state bus tour, Operation Free, a group composed of military veterans, invited Mr. Metcalfe, a fellow veteran, to meet with them.

His response: "As a veteran, I believe that any veteran lending their name to promote the leftist propaganda of global warming and climate change, in an effort to control more of the wealth created in our economy, through cap and tax type policies, all in the name of national security, is a traitor to the oath he or she took to defend the Constitution of our great nation!"

Wait, there's more: "Remember Benedict Arnold before giving credibility to a veteran who uses their service as a means to promote a leftist agenda. Drill Baby Drill!!!"

His stooping to quote Sarah Palin aside, one could argue that disagreeing with veterans -- or anybody -- on an issue debated in public is fair game. The problem with Mr. Metcalfe is that instead of engaging the substance of the topic, he said that a veteran holding the opposing view is a "traitor."

It is an audacious thing for a man who served in the U.S. Army during the relative peacetime of 1980-84 to call other soldiers, at least one of whom fought in Fallujah, Iraq, a "traitor to his or her oath." Now some veterans, understandably, want an apology and VoteVets.org is running a radio ad calling for the legislator's resignation.

Mr. Metcalfe's periodic outbursts make reasonable Pennsylvanians wonder how his constituents could elect a ridiculed firebrand to six terms in the House. Is he really the best -- Republican or Democrat -- that the 12th District has to offer?

Cartoonist Rob Rogers does "Rob's Rough," an early look at his work and his creative process, exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.