While I rarely endorse candidates, there are two good candidates, Liz Watson of Indiana (9th congressional district) and Jana Lynne Sanchez in Texas. They’re not just ‘better than awful Republicans.’ They both endorse Medicare for all and are good on schools (which means they’ll have enthusiasm from the largest Democratic-aligned mass movement remaining).
It doesn’t look like the DCCC is going into these races heavily–no surprise there–even though 2018 could be (hopefully) a ‘wave election’ for Democrats. So it’s up to us (as is usually the case). You can donate to Watson here, and to Sanchez here.