One political cause was the colonists felt their rights were being violated. In England, people can’t be taxed unless they have representatives in Parliament who can speak about and vote on the proposed tax. When the British began to tax the colonists, the colonists had no say regarding the passage of these taxes.
Another cause was the colonists felt the British were restricting their freedoms. The Proclamation of 1763 prevented colonists from moving west of the Appalachian Mountains. Colonists were therefore restricted from getting land cheaply in this region. When the British allowed writs of assistance (search warrants), colonists feared being searched at any time for any reason.
A third cause was the breakdown of communication and trust. After the Boston Massacre and the Boston Tea Party, neither side trusted the other. They weren’t willing to listen to the concerns each side had. This led to harsher laws being passed and eventually to fighting and bloodshed.