Answer:
After the Renaissance, people were enlightened and stood against the traditional authority of the monarch to rule. In order to get rid of the tradition of the king rule which brought chaos and destruction, a need for central government was necessary.
Individual freedom was important as each and every person's right cannot be neglected in a democratic country. Liberty was required for the free man to take decisions. And Equality was important so that the rich doesn't get richer and poor doesn't get poorer.
They provide a channel in which people can communicate directly to their congressmen/ back them to pass legislation on your behalf.
b. Influencing public opinion and forming political action committees
Interests groups form around an issue they want legal action taken. They will use marketing methods to influence public opinion through media and campaigning. If they form a political action committee then they will back political candidates and possibly provide money for a political candidate's campaign. Interest groups in the US include AARP, Family Research Council, and the NAACP.
The absolutists governments in europe tend to believe in Sovereignty, in which there will be a person or a group that held the power that could be considered above laws that couldn't even be remotely apprehended by its people.
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