On whether (or not) there's a "smoking gun" in Donald Trump's involvement with the Russians as candidate and/or President—and whether Americans should care:
The US "Pledge of Allegiance" to the flag lumps together the US as "one Nation under God" and "the Republic" symbolized by the flag. Usually conflated in colloquial usage, Nation and Republic are different things (with "the American State" aside for a moment).
If we are essentially a Nation, and especially if that's a White, Christian Nation — possibly in the sense of "I used to be Catholic but now I'm a Christian" (actual quote) — then President Trump is going an impressive job as Leader of the Nation, channeling the will of the *real* American people and resisting corruption by foreigners generally but also by internal elements on the Nation's territory who are not White and/or properly Christian. Or for more inclusive Nationalists, putting a larger Nation first and over all.
For the Nation, going further a Capitalist Nation, Trump's doing business with the Russians is no big deal, and Russian help for his election would be a neutral or good thing since it helped give the Leader authority over much of the apparatus of the State, returning it to the service of the Nation.
If the US is essentially a Republic with a "mixed Constitution" with democratic elements — even liberal-democratic elements — then messing with elections is a very big deal. Also a big deal would be Trump's trying to use agents and agencies of the State to protect his position as Leader. And a really big deal would be the Leader of the Nation asserting himself over the laws of the Republic and State.
Since most Americans are as double-minded on such matters as the Pledge to the Flag is, this division can get murky. At the extremes, though, it's clear enough, and the resolution (if any) may very well start there if and when small "r" republicans try to remove by impeachment or the 2020 elections the Leader of the Nation.