GOP activists pushing South Carolina Republicans to vote for Sanders in the Democratic primary — to boost Trump
Sen. Bernie Sanders talks about Donald Trump on Conan O'Brien (Screen cap).

On Tuesday, the Post and Courier reported that several local Republican officials and Tea Party leaders in Upstate South Carolina are launching a campaign to urge Republican voters to participate in the Democratic presidential primary — and back Sen. Bernie Sanders (I-VT).

The officials, which include Greenville GOP chairman Nate Leupp, Spartanburg GOP chairman Curtis Smith, and Anderson GOP chairwoman Cheryl Cuthrell, hope that Sanders would be the weakest general election matchup against President Donald Trump, allowing him to attack Sanders' open belief in socialism and shifting the conversation off Trump's own moral fitness for office.

Such gambits have been commonly employed by both parties over the years. In 2008, right-wing talk radio host Rush Limbaugh urged his listeners to vote for Hillary Clinton and deny the nomination to Barack Obama, in what he called "Operation Chaos." And in 2012, former Sen. Claire McCaskill (D-MO) ran "attack" ads against GOP Rep. Todd Akin that were really designed to make him look good to GOP primary voters — securing him a disastrous GOP nomination against more electable opponents.

South Carolina, the first Southern state in the primary calendar, has been described as a must-win state for former Vice President Joe Biden, who commands a strong plurality with African-American voters, and who is relying on a sweep of the South to counteract his likely early losses in Iowa and New Hampshire.

Such a scheme is easy in South Carolina due to its open primary system — voters can choose which party's primary to vote in without registering as a member of that party. Furthermore, GOP officials in South Carolina have canceled their own primary to prevent anyone from mounting a challenge to Trump, which would free up GOP voters to flock to the Democratic primary if they wish.

Leupp told the Post and Courier that if Democrats don't want this interference scheme to go forward, then they "need to help work to close our primaries so it protects them as well as the Republican brand."