Billionaire climate activist Tom Steyer's political action group is targeting Sen. Marco Rubio (R-Fla.) in an anti-Keystone XL pipeline ad set to air Sunday.
NextGen Climate, founded by Steyer in 2013, announced on Friday that Rubio would be the subject of its ad blasting the proposed $5.4 billion pipeline after the senator was selected in an online poll.
The ad is a toned down version of a similar one aired by NextGen earlier this year, which slammed "Chinese government-backed interests" in Canadian oil sands.
The ad with Rubio, which will air Sunday during "Meet the Press" on Florida NBC affiliates in Miami, Tampa and Tallahassee, mentions a number of overseas investors.
The ad presses Rubio to ask pipeline developer TransCanada more questions about where the petroleum transported via Keystone XL will end up. It underscores the possibility that the oil, once refined, will be exported, benefiting foreign companies.
TransCanada has said 100 percent of the crude oil carried through the pipeline will be refined in the U.S.
Rubio was picked as the subject of the ad after Steyer's action group asked its online community to vote, but didn't reveal the final tally of votes. In February, the action group released a list of five lawmakers who could be the target of the ad.
Steyer riled up Democrats on Capitol Hill when Sen. Mary Landrieu appeared on the hit list. The Louisiana Democrat may be essential to maintaining the party's control of the Senate come November.
Democrat strategist and one of Steyer's close advisers, Chris Lehnane, has said one of Steyer's priorities is to help Democrats keep the majority.
The latest attack on Keystone, and Rubio, drew criticism from Keystone advocates, who called the ad a political move for the party.
"Clearly Tom Steyer was told to walk back his attacks on Democrats that support Keystone XL ahead of the upcoming elections, probably because there are so many of them," said Matt Dempsey, spokesman for Oil Sands Fact Check, an industry-backed coalition. "In doing so he has clearly chosen partisan party over principles."