BATON ROUGE, La. (AP) — A national conservative organization has launched new advertising to attack the central message of Democratic U.S. Sen. Mary Landrieu's campaign, that her clout is invaluable to Louisiana.

The Americans for Prosperity ad, which begins airing statewide Wednesday, says Landrieu's position as leader of the Senate energy committee hasn't helped Louisiana.

The 30-second spot echoes Republican criticism that Landrieu's chairmanship hasn't changed anything in the Senate on energy issues.

Landrieu's support of the Keystone XL oil pipeline hasn't forced a Senate vote on advancing the long-delayed project. Meanwhile, Landrieu's opposition to President Barack Obama's regulatory plan to cut carbon dioxide pollution hasn't altered the proposal.

Landrieu has said she will keep fighting on those issues, and she's said her seniority and chairmanship draw attention to the debates and give her leverage.

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