We have a Clinton-era Treaty with Ukraine for mutual assistance in criminal investigations. So President Trump, as Lt. Col Vindman admitted in his testimony, had every right to ask for an investigation.
Why are so many Democrats involved in Ukraine is the question. The Biden's, the Kerry Klan, Pelosi, Schiff. Follow the money.
As far as a "Chinese vassal", look no further than Bloomberg. Biden is done, he was never really going to win the nomination. But Bloomberg could buy it, for his pal Xi that is.