Damar would probably win the first elections and Ghemor wouldn't have any real power to do the damage.
I don't think he would support the coup. I think he would support the Mar'kuu Group (if it existed at all, Damar's presence would most likely change the whole political scene of Cardassia) but a coup wouldn't be needed.
If he didn't support the Mar'kuu Group, it wouldn't destroy his friendship with Jarol. She's better than that. And I am not sure she would got involved in politics at all if he were alive.