A feud is brewing between Sen. David VitterDavid Bruce VitterBiden inaugural committee to refund former senator's donation due to foreign agent status Bottom line Lysol, Charmin keep new consumer brand group lobbyist busy during pandemic MORE (R-La.) and the Service Employees International Union (SEIU).

After the SEIU ran an ad critical of Vitter in Thursday's New Orleans Times-Picayune, Vitter shot back by criticizing the SEIU in a blog post, calling it a "weapon" for liberals.

Now, SEIU is firing back.

"Sen. Vitter: You can run for re-election, but you can't hide from your voting record," said Helene O'Brein, president of the local SEIU chapter.

"Sen. Vitter was right about one thing though--the election is more than 500 days away. That's why working families throughout Louisiana are uniting now to hold politicians accountable. We need to make sure in November 2010, we elect leaders who will stand up for hardworking Louisianans."

Vitter represents a solid target for SEIU, because he is one of the most vulnerable incumbents up for reelection and has actively opposed union priorities like the State Children's Health Insurance Program (SCHIP) and the union-organizing Employee Free Choice Act (EFCA), or card-check.

The ad and the crossfire could be the beginning of a big campaign by SEIU to take him out in 2010.

-Aaron Blake