It's a conundrum because he wants to blame Obama for something bad, but if he does he'll have to admit (which he hasn't done) that the Russians helped him win the election.
His point is valid, though. If the Russians were trying to help Trump win the election, it would have been done while Obama was president. It would have been done while the Obama administration sat idly by and watched. And we now know with certainty that Trump, nor his administration, had anything to do with it.
Here is everything you need to know about Donald Trump’s view of the law in one scene:
The President also asked McGahn in the meeting why he had told Special Counsel’s Office investigators that the President had told him to have the Special Counsel removed. McGahn responded that he had to and these conversations with the President were not protected by attorney-client privilege. The President then asked, “What about these notes? Why do you take notes? Lawyers don’t take notes. I never had a lawyer who took notes.” McGahn responded that he keeps notes because he is a “real lawyer” and explained that notes create a record and are not a bad thing. (page 117)
What sort of man employs lawyers who intentionally don’t keep notes, you might wonder?
Not me. Vlad called me in person, and sent a couple of guys to the house.What do you mean? I know I voted for Trump because some subliminal meme or gif or billboard told me to. Didn't you?
Edit: And actually I think it is because Frank Zappa is a Russian stooge. He did it to me.
Poyakheli in 2020 Frank.