Sen. Tom Harkin (D) took some veiled jabs at fellow Iowa Sen. Chuck Grassley (R) Wednesday. 

"The big money interests are lining up to dump millions upon millions of dollars into Iowa to protect their friends in the Senate, who'll keep things the way they are," Harkin wrote in a fundraising pitch on behalf of Roxanne Conlin, Grassley's Democratic challenger. "Roxanne's not taking their dirty money. Her campaign is fueled by support from people like you and me."

Harkin doesn’t mention Grassley directly, but notes he needs a "partner" in the Senate "as we take on critical issues like the Gulf recovery, reforming Wall Street, and making sure that Iowans can find good paying jobs again."

Grassley is expected to have a tougher reelection race than usual against Conlin, a wealthy trial lawyer.

The five-term incument sent out his own pitch Wednesday, noting that national attention is being paid to this quarter's results.

"A great deal of press attention will be given to how successful we have been compared to my opponent when those numbers are released," Grassley wrote.

He asked his supporters to donate so that he can "continue the fight to secure our borders and oppose amnesty."