Anyway: I find it rich of Republicans to complain of a “pattern” of investigating Trump when Trump and his officials themselves are the ones who keep stepping in these waters.
Indeed, you’re right Russiagate didn’t find direct evidence of collusion by Trump himself. Good for him: and for that reason, no impeachment resulted.
However, the probe turned up enough evidence of Russian election interference generally (and other lawbreaking) to result in 37 indictments, 7 convictions, and 5 prison sentences. Heck, let’s not forget the porn star payoffs by Cohen that most definitely didn’t involve any direction from Trump himself (wink wink). A small concern compared to conspiring with Russia, but still a campaign finance violation. Manafort the Trump campaign chair was dinged on tax fraud etc. Bottom-line: Mueller did his job, did it well, and this wasn’t a hoax.
Then Trump went and made the infamous Zelensky call the day after Mueller’s congressional testimony. You can’t make this stuff up.
So when it came to Ukraine, we actually had smoking-gun evidence of Trump himself pressuring the Ukrainian President re: Biden, which is why impeachment then resulted. (There were other backdoor channels by Giuliani, etc.) Still Republicans didn’t care and aided and abetted every effort to obstruct the investigation.
This election interference stuff is complex and flies over the heads of most Americans (unlike the easy-to-grasp crimes of breaking and entering & wiretapping: see Watergate), but that is no reason not to investigate it, document it, and call it out.
Strip away every other complaint about Trump that I’ve listed, and Ukrainegate alone is enough to find Trump unworthy to hold the office of President, as Senate Democrats and Sen. Romney found.
Other moderate Republicans offered some version of “let the voters decide.” But that argument eviscerates impeachment.