(CNN) -- In Louisiana, Republican Bill Cassidy is running to retire Democratic incumbent Mary Landrieu. But national Democrats are hoping the GOP lawmaker's stance on raising the Social Security retirement age will stop that from happening.
The Democratic Senatorial Campaign Committee will unveil a new television ad in the Bayou State on Thursday that hammers Cassidy for favoring increasing the age at which retirees can collect Social Security benefits to 70. At Tuesday's debate, Cassidy said he did not support changing benefits for those at or near retirement, but suggested that benefits for younger workers would need to be revamped.
Landrieu drew a sharp contrast with Cassidy at that meeting, saying the idea of having people work until they are 70 was "very bad policy."
The DSCC is reinforcing that message with its latest ad in the hotly-watched race, one of the key battlegrounds for majority control of the Senate this fall. "When it comes to seniors, Congressman Bill Cassidy has a plan: Raise the retirement age for Social Security and Medicare to 70," the narrator grimly states.
The 30-second spot is part of a $2.5 million buy and is running statewide.
Landrieu's campaign on Thursday unveiled a new website, 70WillHurt.com, to highlight Cassidy's stance on Social Security.
The Cassidy campaign, meanwhile, accused Landrieu of trying to "have it both ways" when it comes to Social Security, pointing out that the Democrat previously expressed support for the Simpson-Bowles deficit reduction report that would have gradually raised the retirement age.
A CNN/ORC survey released last month found Landrieu leading Cassidy 43 percent to 40 percent among likely voters, with the other Republican candidate in the race, Rob Maness, pulling nine percent. With no primary, all the contenders for the Senate seat will be on the ballot this fall. If no candidate receives a majority of the vote on Election Day the top two finishers will advance to a December runoff. In a head-to-head matchup, Cassidy leads Landrieu 50 percent to 47 percent among likely voters.