Las Vegas businessman Danny Tarkanian (R) argues he has the best chance of defeating Senate Majority Leader Harry Reid (Nev.) in November.
Tarkanian made the electability pitch in a last-minute fundraising appeal to supporters, released in the wake of a poll that shows him with a lead over Reid in a potential general election clash.
Tarkanian tops Reid 43-37 percent, in a match-up polled in the latest Mason-Dixon/Las Vegas Review-Journal survey.
Tea Party favorite Sharron Angle (R) leads Reid by three points, inside the poll's margin of error, and Reid leads former state Sen. Sue Lowden (R) by one point.
The fundraising appeal, which cites Tarkanian's performance in the poll, asks voters to help pay for a telephone town hall Monday night, and "to contribute what you can afford to retiring Reid."
Just a month earlier, Lowden had a commanding lead in the primary race, but her claims that residents could barter for cheaper healthcare and the media storm it created precipitated her drop in the polls.
Tarkanian isn't the only GOP Senate candidate trying to close the gap with an electability argument ahead of Tuesday's vote.
In a recent TV ad, California GOP Senate candidate Tom Campbell 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.