Politicians goal is to influence or persuade people to think or act a certain way. This is done by creating fear and anger between you and the two sides. By doing this, they solidify their base and make it more difficult people to think or act rational. Like making you going along with something you normally wouldn’t, but you do to support your party or supposedly hurt the other party.
This is an example of one of the 48 Laws of Power.
Law 27: Play on People’s Need to Believe to Create a Cult like Following
People have an overwhelming desire to believe in something. Become the focal point of such desire by offering them a cause, a new faith to follow. Keep your words vague but full of promise; emphasize enthusiasm over rationality and clear thinking. Give your new disciples rituals to perform, ask them to make sacrifices on your behalf. In the absence of organized religion and grand causes, your new belief system will bring you untold power.
You subconscious mind or reptilian brain is the reason this works on people. How and why this is so, that is a topic for another conversation.