Law Enforcement could be their own faction or that could fall under 'political establishment'. Depending on how complex you want to get. If you really want to go all in, you could combine"House of Cards" and "The Wire" and really cover every aspect of political society

You could definitely have a powerful local constabulary or police station that has needs of its own--

* the police are constantly harrassing aliens of certain species

* representatives of the aliens are demanding that the new candidate (for mayor, planetary governor, what have you) stop the police from doing it

* if you came out in favor of the aliens, the police might be against you

* if you came out in favor of the police, the local populace might be against you

That's politics!