Wisconsin Senate candidate Ron Johnson (R) maintains a large lead over his primary rival despite allegations he used bribery and coercion to win the state party's endorsement at its May convention.

Johnson leads businessman Dave Westlake 49 percent to 11 percent in a Public Policy Polling survey of 400 GOP primary voters conducted June 26-27. Neither candidate is well known, which Sen. Russ Feingold (D-Wis.) must appreciate. More than half of the respondents said they had no opinion of Johnson, while 80 percent were "not sure" about Westlake.

Tea Party activists have recently been griping about how Johnson, who has never before sought public office, came out of nowhere to become the frontrunner for the GOP nomination to face Feingold.