SPRINGFIELD-U.S. Sen. Mark Kirk said Thursday that U.S. Rep. Tammy Duckworth, a fellow military veteran, was out of line for her implication that Republican Bruce Rauner is a “deserter” for investing some of his personal fortune in the Cayman Islands.

The Highland Park Republican also told Republicans following a GOP unity breakfast in Springfield that the Democrats’ main message from Thursday of class warfare wouldn’t sell with voters in November.

One of the most inflammatory moments of Governor’s Day came when Duckworth, a disabled Iraq War veteran, said Rauner’s investments qualify him as a “deserter” if his intent was to avoid paying U.S. and state taxes.

Rauner has denied that was the case and said he has fulfilled his American tax obligations.

“If we use comments like ‘deserter’ and ‘traitor’ that normally those crimes have a capital punishment consequence, I’d say that rhetoric is probably too overblown for a country that wants to stick together and hang together,” Kirk said.

The state’s junior senator also said the attacks Democrats have leveled both on the wealth of Rauner and U.S. Senate candidate Jim Oberweis, a dairy magnate and state senator running against Sen. Dick Durbin, won’t fly in November.

“The point of America is that we all want everyone to be wealthy,” Kirk said. “We’re a success-driven country. We want to make sure that we Americans are not jealous of our fellow citizens. We don’t want to pull people down just because they’re successful. The class warfare message has never really worked well with the American people.”