Sen. Lamar Alexander (R-TN) said on Sunday that it bothered him that President Donald Trump pushed the Ukrainian president to investigate a long-debunked conspiracy theory surrounding the Democratic National Committee server hack in the 2016 election , calling it a “mistake.”Alexander, who voted against allowing additional witnesses in the Senate impeachment trial last week despite saying he believed the president’s behavior towards Ukraine was inappropriate, appeared on NBC’s Meet the Press to defend his decision. Reiterating his assertion that more witnesses and evidence weren’t necessary as the Democrats had already proven their case, the Tennessee Republican added that he was going to vote to acquit the president because he was “very concerned about any action that we could take that would establish a perpetual impeachment,” adding that when you “start out with a partisan impeachment, you're almost destined to have a partisan acquittal.”Having all but assured Trump's acquittal, Alexander, who is retiring at the end of his term, detailed where he thought the president's actions were wrong:“What I believe he did, one, was that he called the president of Ukraine and asked him to become involved in investigating Joe Biden ,” Alexander told host Chuck Todd. “The second thing was, at least in part, he delayed the military and other assistance to Ukraine in order to encourage that investigation.”“Those are the two things he did,” he added. “I think he shouldn't have done it. I think it was wrong. Inappropriate was the way I'd say -- improper, crossing the line. And then the only question left is who decides what to do about that.”The conservative lawmaker, however, repeated his belief that this didn’t rise to the level of impeachment and that Trump’s fate should be left to the ballot box, saying “the people” should decide whether to punish the president for his actions.“You know, in the phone call, there's one thing on the phone call that I'm surprised, frankly, hasn't been brought up more by others,” the Meet the Press anchor noted at one point. “This -- the mere mention of the word ‘CrowdStrike,’ is a Russian intelligence sort of piece of propaganda that they've been circulating.”“Does it bother you that the President of the United States is reiterating Russian propaganda?” Todd asked, referencing the fringe-right theory that the DNC server is currently in Ukraine and wasn’t hacked by Russia.“Yes. I think that's a mistake,” Alexander responded. “I mean, if you see what's happening in the Baltic states, where Russians have a big warehouse in Saint Petersburg, in Russia , where they're devoted to destabilizing western democracies.”“I mean, for example, in one of the Baltic states, they accused a NATO officer of raping a local girl,” the senator continued. “Of course, didn't happen. But it threw the government into complete disarray for a week. So I think we need to be sensitive to the fact that the Russians are out to do no good, to destabilize western democracies, including us, and be very wary of theories that Russians come up with and peddle.”