It’s been a rough week for former Wisconsin Gov. and GOP Senate candidate Tommy Thompson, who learned tonight that GOP presidential nominee Mitt Romney has friends who are unafraid to lash out at other Republicans in his defense.

On Wednesday, Thompson blamed Romney for his losing s
ignificant ground in multiple polls to Democratic opponent Rep. Tammy Baldwin,  including a Marquette University poll that flipped from him leading by 9 points last month to trailing by the same margin this month. Thompson told a Madison TV station, “Whether you’re a Democrat or Republican, if you’re a standard-bearer for the presidency is not doing well, it’s going to reflect on the downballot.”

Top Romney surrogate and former New Hampshire Gov. John Sununu struck back at Thompson, who has created friction between himself and the presidential campaign, by telling CNN tonight that Thompson “sounds like Barack Obama trying to blame it on somebody else.”

“Campaigns go up, campaigns go down. I’m sure Tommy will be fine in the long run,” Sununu said to CNN’s Anderson Cooper. “I think Romney’s doing just fine. He’s dead even with [Obama] in polls out there.”

A NBC News/Wall Street Journal/Marist poll released earlier this evening, showed Obama leading Romney by 5 points among likely voters and 8 points among a wider sample of registered ones.

Thompson finished a tough four-way primary last month with only $352,000 in cash on hand and has spent much of the past month fundraising. Republicans need him to take the seat being vacated by Democratic Sen. Herb Kohl to have a chance at gaining control of the Senate, and upsetting the Romney team in Wisconsin, home to vice presidential nominee Paul Ryan, likely is not helpful.

Roll Call rates this race a as Tossup.

The National Republican Senatorial Committee assisted Thompson with a $400,000 ad spot that debuted today in the Badger State.