would do the trick, no? If it's just a 'mail-in' convention, then why go through the sham at all?

Here's why.

In 1968, the popular republican Senator Tom Kuchel was up for re-election in California, and was considered a shoo-in. The Democrats had to resort to bribes to get a prominent Democrat (Alan Cranston) to file for the D primary (He was promised he wouldn't have to spend a dime or disrupt his life to campaign).

The R primary voters, in their wisdom, chose to reject Sen Kuchel and nominate in his place the wingnut and just general nut Secretary of Education Max Rafferty.

Cranston campaigned and won easily and held the seat for 24 years.

All because there was no R state convention where party elders could apply some reason against politically suicidal primary voters.