Are Republicans largely cowards or are they co-conspirators with Trump?

Tax cuts, restriction of human rights, deregulation, etc.

For many (most?) Republicans, Trump is very much an example of the ends justifying the means. They might not like his methods, but only because he's more overt about it than they'd like. They'd prefer to screw over the country a little more quietly.

i tend to believe their behavior is "overdetermined"

For many, it probably is both.

But Lindsey Graham is a yellow-bellied coward

If the Democratic Party operated like this (with a corrupt Dem POTUS), I'd leave the party. Correct is correct and the Rule of Law is The Rule of Law.

thuglicans don't have to really worry about their mostly dumb as a bag of hammers and racist base, because they KNOW that they can always get help from the ruskies or from the rest of the tRumpthuglican party to rig, vote destroy, Dem voter-base hack/destroy, tamper with election machines or Dem voter-suppress enough Dem votes away to win the presidency.

tRumpthuglicans would love to rich-white right-wing male this country to DEATH.

so I would have to say "Yes!"

Look at how much they've been able to get away with while Trump distracts and divides the electorate with his endless spectacles.

And they are proving it.