If you are in a "solidly X" state, downballot voting STILL MATTERS.
County stuff, City stuff. Your local schools. The water board. It all still matters and your vote always matters.
I suspect US Mastodon probably has a higher percentage of voters than the general public, but I'll still say it. The city I live in actually just barely overflows the Rose Bowl. All those city votes matter. Sometimes with more of an effect than the Federal stuff. California Initiatives? Kinda vital.
Vote.