NextGen Climate Action, the super PAC started by progressive environmental activist and billionaire Tom Steyer, is running an ad against Florida Sen. Marco Rubio about his support of the Keystone XL pipeline. The ad will air during "Meet the Press" this Sunday on local NBC television affiliates in Miami, Tallahassee and Tampa.

The ad says: "Sen. Marco Rubio says Keystone will help make America energy independent. But under oath, TransCanada can't commit to keeping Keystone oil in the U.S. The oil lobbyists take Rubio for a sucker." It ends, "Sen. Rubio, don't get taken for a sucker."

Earlier this year, Rubio called the Keystone XL pipeline a key part of his economic agenda. “The interstate highway system of the last century helped foster an explosion of economic opportunity," he said. "What we need now is an interstate energy pipeline because it could have a similar impact in this century."

NextGen and other environmental groups contend that the Keystone XL pipeline will only create 35 permanent jobs.

NextGen Climate Action asked its supporters to vote for which elected official they wanted the organization to target in February. There were five options — including Democratic Louisiana Sen. Mary Landrieu — and NextGen promised to run an ad in the state of whichever legislator received the most votes. Rubio, who is not up for reelection until 2016, was the clear winner.

The other potential ad targets were West Virginia Rep. Shelley Moore Capito, former South Dakota governor Mike Rounds and Georgia Rep. Paul Broun.

Shane Red Hawk of the Sicangu Lakota band of the Rosebud Sioux, center, waits with other members of the "Cowboy and Indian Alliance" to begin a horseback ride in protest of the Keystone XL Pipeline near the Capitol Reflecting Pool in Washington, D.C., on April 22. (Jim Lo Scalzo/EPA)

Officials from NextGen are not disclosing the size of the ad buy at this time.

Steyer announced this year that he planned to spend as much as $100 million during the 2014 midterms to make the environment and climate change bigger issues during this election season. As The Washington Post reported this week, Steyer's chief goal — with Keystone XL and the midterms — is winning. "I've spent my life up to 22 playing a lot of sports so I really care about wins," he said. "I don't think there's any way you look at elections and don't look at it in terms of wins and losses."

Members of the Cowboy and Indian Alliance rode on horseback through Washington, D.C., this week, protesting construction of the Keystone XL pipeline. The protest is a part of "Reject and Protect" week, which has brought many anti-Keystone groups to D.C.