North Carolina Democrat Cal Cunningham is focused on the general election ahead of next week’s Senate primary runoff, which recent history has shown is not a winning strategy.

Cunningham, the Democratic establishment's pick, is currently on a "Beat Burr" tour, where he's talking up his prospects of unseating Sen. Richard Burr (R-N.C.).

"Democrats must nominate the strongest challenger possible," he wrote to supporters in an e-mail Thursday. "We're going to take on Senator Burr in all 100 counties across North Carolina."

Cunningham faces Secretary of State Elaine Marshall (D) in the June 22 runoff.

Other candidates have tried closing with the electablity argument in recent primaries but without success.

Las Vegas businessman Danny Tarkanian (R) argued in the days leading up to the Nevada GOP Senate primary that he had the best chance of defeating Senate Majority Leader Harry Reid (Nev.).

And in his final TV ads, California GOP Senate candidate Tom Campbell (R) cited a poll that showed him leading Sen. Barbara Boxer (D-Calif.) by seven points as a reason for Republicans to vote for him in the primary.

Both men lost their races.