Trump gave money to Rahm’s campaign because the alternative candidates would be a disaster, and Trump has business interests in Chicago, including Chicago’s version of Trump Tower. He wants to have some influence and voice in what happens with the business climate in the city of Chicago. He has vested financial and real estate interests in Chicago and he wants to protect them politically, as best he can. He is a shrewd and practical businessman. If Carole Mostly Fraud or Gary Chico got into office, it could be very detrimental to doing businesss in Chicago. Rahm will be much more practical and is the least of three evils by far.
Please read the article linked in Post 18.