As we noted over the weekend at the Netroots Nation conference, Democrats are content to fight fire with fire when it comes to super PAC spending.

DCCC chairman Steve Israel (courtesy of CQ-Roll Call, Inc.)

Democratic Congressional Campaign Committee Chairman Steve Israel (N.Y.) on Thursday slammed Republicans on the heels of the recent news that casino mogul Sheldon Adelson is giving $10 million to the pro-Romney super PAC “Restore Our Future.”

“Instead of United States of America, maybe he wants it to be ‘United States of Adelson,’ ” Israel said in an appearance on MSNBC.

Israel made the remark in response to a question about the spending of the Democratic super PAC “House Majority PAC”, which played an active role in the Arizona special election.

“It’s the one thing that keeps me up at night,” Israel said of super PAC spending; he then pivoted to argue against the influence of Republican outside groups.

On Wednesday, Wisconsin Gov. Scott Walker (R) argued that Democrats’ win in the Arizona special election does not have any national implications because the race was largely a “personality-driven” one.

Israel fired back Thursday that the contest was a referendum on Rep. Paul Ryan’s (R-Wis.) budget blueprint and a preview of things to come this fall.