Which of the following is NOT a formal or informal source of presidential power?

The correct response highlights that the presidential authority to raise revenue is primarily a formal power granted by the Constitution and Congress, rather than being classified as an informal source of presidential power. The power to raise revenue, such as through taxation and budget proposals, is a specific responsibility that falls under the legislative branch, where Congress ultimately controls fiscal policy.

In contrast, the other options represent informal sources of presidential power. Access to the media allows presidents to shape public perception and communicate their policies directly to the electorate, thereby enhancing their influence. Similarly, precedents set during previous administrations provide a framework that modern presidents can rely upon, giving them a historical context to inform their decisions and actions. Lastly, public support acts as a significant informal power; a president who enjoys high approval ratings can more effectively persuade Congress and the public to back their initiatives.

Thus, identifying the presidential authority to raise revenue as a formal power clarifies its distinct difference from the more nuanced and adaptable informal sources of power available to presidents.