Schweitzer says he'll support "any decision that Steve Bullock makes."
The National Republican Senatorial Committee raised $3.2M last month.
“I have nothing to announce with regard to my future political plans,” the ex-senator said.
Officials expressed interest in seeing Jim Messina serve as a placeholder until November.
Sen. Thad Cochran (R-Miss.) is starting off in a weak position against a tough Tea Party challenger, according to a new poll conducted for the conservative online magazine Human Events.
Cochran is tied with Tea Party-backed Chris McDaniel at 40 percent among GOP voters who've voted in a recent Republican primary, not a good spot to be in for the long-term incumbent.
Twenty-six senators introduced a bipartisan bill that would impose new and tougher sanctions.
Georgia Senate candidate Michelle Nunn (D) is fundraising off Rep. Jack Kingston's (R-Ga.) comments that poor children should have to "sweep the floor" in to be eligible for a free lunch program.
Kingston, one of several Republicans running for the Senate, told local Republicans last weekend that there should be "no such thing as a free lunch" for poor children.
"Why don’t you, you know, have the kids pay a dime, pay a nickel, instill in them that there is, in fact, no such thing as a free lunch. Or maybe sweep the floor in the cafeteria," he said.
The controversial comments were picked up nationally. Now Nunn, a former charity CEO, is using them to raise funds for her own race.
He said the "Duck Dynasty" star is being targeted just like the Obama rodeo clown.
"It becomes evident that she really has no idea what she’s talking about," Bevin said.
Georgia Republican Rep. Jack Kingston, a candidate for Senate, suggested that low-income students either pay or work for their subsidized school lunches to teach them that “there is no such thing as a free lunch.”