Yes, this needs to be investigated. This was clearly a request for a quid pro quo arrangement. Pay me this and I'll do that for you. Very illegal. In case there's any doubt about that...
In 1976, announcing the Supreme Court's landmark Buckley v. Valeo decision, Chief Justice Warren Burger set this standard for corruption: "the reality & appearance of improper influence stemming from the dependence of candidates on large campaign contributions."
The current chief justice, John Roberts, had led an effort to tighten that broad language. Roberts, delivering the McCutcheon v. FEC ruling last year, defined corruption as "a contribution to a particular candidate in exchange for his agreeing to do a particular act within his official duties."
He was describing a quid pro quo – the donor's money in explicit exchange for the politician's official favor. It's a felony.
Just to be clear, John Roberts, Chief Justice of the Supreme Court of the USA defined corruption as "a contribution to a particular candidate in exchange for his agreeing to do a particular act within his official duties."