It has become a third rail or self-censored topic because Putin has compromised a broad swath of politicians. Trying to indict Trump leads the the grim reality that much of the landscape has been corrupted. Thus, the GQP don't care, especially as Fox takes cues from Putin and indoctrinates its viewers accordingly.

Been there, done that, and few gave my assertions much credit. Even now they tend to shrug or laugh about the truth of it and no more.

I think it's as well-publicized as the way the Republican party claim to be deficit hawks and fiscal conservatives, but only when we have a Democrat in the White House. When it's one of their own, they're even more free-spending than the Democrats. (Of course, what they're willing to spend money on is the real crux of the matter; they spend trillions for the military while cutting taxes for the wealthy, but not a dime for social programs or the bottom 99%.)

I've seen numerous editorial criticisms of Trump's cozying up to dictators, but perhaps you're right that the politicians themselves don't get into it as much as they could or should. There seems to be a feeling that Americans don't know or care about foreign policy and politics beyond their own narrow interests, and sadly that's mostly the case. I'm not calling voters stupid (although.... 74,000,000 voted for Trump a second time...), but most Americans are terribly provincial and don't look far beyond what they conceive to be the most important issues, whether that's the price of gasoline or so-called "moral" issues.

There's also the tendency to back their own side, no matter what (this goes for both parties). Just look at the evangelicals; they did a complete 180 over whether personal morality should be a consideration in a person's fitness for office, from insisting that Bill Clinton's affairs were shocking and should get him impeached, to giving a shrug and a "meh" to Trump's much more public and much more disgraceful behavior (remember "grab them by the pussy"?).