From Renato Mariotti at POLITICO Magazine:
It’s easy to see why Trump’s alleged conduct has generated outrage and why lay people have rushed to describe it as categorically criminal. Using presidential power to withhold aid to a nation that was recently invaded by Russia unless they investigate your political rival sounds like the definition of a criminal quid pro quo. The possibility that Trump pressured another nation to interfere in the next presidential election on his behalf—not long after the completion of a multi-year investigation into interference in the 2016 election by Russia on his behalf—is jaw-dropping.
But the impulse to label this as a potential crime, as many respected former prosecutors and legal analysts have done, is flawed legally and even strategically. Even if true, this is not a case that would end up in a criminal proceeding even if Trump was no longer in office.
Let’s look at the actual law.