O'Leary has only a superficial resemblance to Trump. He is much more urbane and socially liberal. If I was going to compare him to anyone in recent US politics he would be more like Steve Forbes. O'Leary has very hardline rightwing economic views but they are orthodox rightwing views, he would never bash NAFTA or TPP etc...
The prospective Conservative candidate who is really the most Trump-like would be Doug Ford
These are fresh comparisons that are absolutely right.
It seems though anyway that O'Leary is leaning against a run.