The most recent Iowa polls show Mitt Romney leading with just above 20 percent, but fellow contenders Herman Cain and Rep. Michele BachmannMichele Marie BachmannKlobuchar urges CNN town hall audience: 'That's when you guys are supposed to cheer, OK?' Michele Bachmann praises Trump: Americans will 'never see a more godly, biblical president' Will Biden lead a 'return to normalcy' in 2020? MORE (R-Minn.) have battled it out for second place over the past month.

Grassley already told The Hill he was unlikely to endorse this cycle. He did not endorse in 2008. Grassley is an influential lawmaker in an important early-voting state and he acknowledged that "maybe" his support could help pull Iowa Republicans together behind one candidate, but said, “I’ve made a decision” not to get involved.

“I’m not going to endorse anybody,” Grassley said. “We’ve got several good candidates and I think I’m willing to let the system go, and I also feel that at this point, my involvement would not make a significant difference because Republicans are divided among so many different candidates."

He added, "I wouldn't say anybody's been aggressive courting [my endorsement].”

Although he said he met with him, Romney did not ask for his support and neither did Perry. Newt Gingrich did, and "I think" Rick Santorum did as well, Grassley said.