Many of the big boys have already signed this open letter to the RNSC. I'm signing it as well. You can sign by commenting to that effect.
Dear Senator Cornyn,
We the undersigned believe that the National Republican Senatorial Committee should be committed to serving ALL the members of the Republican Party.
Additionally, the NRSC should be focused on defeating Democrats, not Republicans. Towards that end, we believe it was completely inappropriate for the NRSC to endorse a candidate in the Florida primary race.
Therefore, we request that both you and the NRSC alter your position on the Florida Senate race, maintain neutrality, and promise to spend no money directly or indirectly in that race.