You run the best candidates you can. Sometimes, nobody worthwhile comes forward.
But historically, Democrats have "moved to the center" in election years, only to revert back to form following the election. This has not happened this year, presumably because the Left is relying on a small cadre of VERY WEALTHY, VERY LEFTIST donors, who are providing MILLIONS to support extremeLeftist candidates. They don't want to hear (or pay for) "centrist" political positions from "their" candidates.
Hence, we have Democrats who continue to peddle open borders, tax increases, impeachment of the President, and other positions antithetical to both the Right and to rational humans.
One can only hope that Democrats snatch defeat from the jaws of inevitable victory and we have a repeat of 2016. I personally will vote early and often for every ******* Republican on the ballot.