As Reagan once explained, when someone donates to your campaign, they are supporting you, not visa versa.
Reagan wasn't a businessman in NY City, New Jersey, and elsewhere that needed support of politicians on both sides of the aisle in order to be able to see his projects brought to fruition. People donate to candidates because they support their policies, but they also donate, hoping they will be able to come back and ask for a favor at some point. I doubt Reagan didn't realize that when he took supporter's money.