Answer: participating in political campaigns; engaging in planned protests.
Political parties and special interest groups can be an effective way for common citizens to express their political opinions and to try to influence the election or legislation process.
Political parties and special interest groups work within the framework of the law, therefore, they can only take part in legal actions, such as peaceful protests and campaigning.
Bribing members of Congress or revolting against the government, however, are actions that are outside of the legal limits, and therefore not condoned by political parties or special interest groups.