A political football - Idioms by The Free Dictionary
a political football
A problem or situation that causes an argument between different political parties, often in an attempt to gain an advantage. It didn't take too long before the issue of property taxes turned into a political football for the candidates.
a poˌlitical ˈfootball an issue or a problem that causes argument and disagreement and that different political groups use to gain votes: It is sad that education is still being used as a political football, instead of action being taken to improve it.