As far back children we are taught to avoid two subjects in polite conversation politics and religion.
The topics are considered taboo by some because people hold such strong opinions about them. So, in order to keep the peace, we are told to avoid talking about them in public. It is considered the polite thing to do.
Wars are fought are fought over politics and religion because they are such personal subjects. People feel deeply about them and it is hard for them to see opposing views. They may feel threatened by others' differences and cling to what they know.
Some people feel comfortable with their opinions and are threatened by opposing ideas. They shut out new ideas to protect themselves. Other ideas are not considered or considered and quickly rejected.
In political circles, conversations about hot button subjects are often shelved after lengthy, heated debates that don't go anywhere. Occasionally, the two sides can find common ground on some issues.
Politics are a magnet for people with extreme views. They may want to voice their opinions and sometimes do so in unacceptable ways. The chance of finding common ground is unlikely.
You may wonder how politicians ever get anything done in this type of environment. What ends up happening, is that politicians on both sides of the argument stack the sides with their supporters. In American politics the process allows citizens to vote for people who they believe best represent their views. They can also contribute money to their campaigns and volunteer their time stumping for them.
Finding enough supporters for your position will enable you to influence politicians to pass legislation that will further your agenda. This can be done with a lot of time, effort and devotion to your cause.