Public opinion is the collective expression of the views, beliefs, and attitudes of a group of people on a particular issue or set of issues. In a representative democracy such as the United States, public opinion plays an enormous role in the actions of government officials. Members of Congress and the president (and politicians at the state and local levels) are elected by the people and need to know what the people they represent want and need. Likewise, the people need an avenue for communicating with public officials so they can let those officials know what issues they care about and what actions they want taken on those issues. Public opinion alerts members of Congress and the president of what legislation and policies the American people think are necessary and how they need to adjust policies that are being considered. It also alerts the judiciary as to how well a court decision will or will not be accepted by Americans.
Knowing public opinion on an issue is not a guarantee that public officials will follow it. While government leaders do tend to follow the direction of public opinion, there are exceptions. In such situations, government officials may be unable or unwilling to reconcile public opinion with their own views or with a position they think is politically preferable for other reasons. Other times, officials may wait to act or to take a stand on an issue, wishing to see if public opinion shifts, which it can do quickly.
For the executive branch, public opinion is sometimes used to determine political strategy. When public opinion demonstrates strong approval of the job the president is doing, the president may capitalize on those positive feelings to push forward a certain policy goal that encountered roadblocks at another time. Conversely, a president might also try to turn the tide of public opinion in favor of a policy by using the persuasive power of the office. Theodore Roosevelt relished what he called the bully pulpit, a president's unique ability to command the attention of the public and shape public opinion. Successful presidents use that position to try to lead the public to favor their policy goals.
In the legislative branch, public opinion can sway whether a member of Congress chooses to sponsor a bill or to vote for or against one. Given the desire of most sitting members of Congress to win reelection, they pay more attention to the views of their constituents than to those of a broader public. In the House, representatives serve two-year terms. As a result, constituents are more likely to remember if their opinion was heeded when the member comes up for reelection. Senators, who serve for six years, have more time to address votes that run counter to the views of substantial numbers of constituents but still are careful not to go against strongly held public opinion in their states.
The judiciary is more removed from everyday politics, making the power of public opinion less of an issue in court cases than in executive or legislative actions. Still, some political science studies have shown that Supreme Court decisions in highly publicized cases typically reflect the majority of public opinion. However, there is no definitive pattern in the relationship between majority opinion and court decisions. It is certainly the case that public opinion of the court itself can change after a widely reported decision, particularly if it is on a highly controversial issue.