Carbon Tax Is Tough Sell for Climate-Friendly Republicans

All eyes are on Utah Republican Sen. Mitt Romney to lend support to a political third rail for his party: a nationwide tax on carbon.

Advocates for the tax are working hard to sell their idea to make big polluters pay for the climate-warming gases that they send into the air. But supporting any new taxes, particularly on a divisive issue like climate change, will be a hard pill to swallow for Republicans, even for those who admit that Congress must act to control rising temperatures.

Romney, the 2012 GOP presidential candidate, supported a 2017 tax-and-dividend plan from two ...