washingtonpost.com/national-secur…
He wanted the Ukrainian government to start a criminal investigation.
Such an investigation is being requested, specifically to give the President electoral advantage over his most likely 2020 rival.
Asking someone for it is solicitation of a campaign finance violation.
The government of Ukraine certainly counts as a foreigner for purposes of campaign finance law.
1) Protecting the President's communications. See this:
2) Stonewalling to protect Trump.
3) Denying Congress info on an ongoing law enforcement investigation.
There could be more. Stay tuned.