Congress NAILs the President

NAIL is a mnemonic device for four ways by which the legislative branch oversees or checks the executive.

• Nominations. The Senate must confirm presidential nominations to high-level executive posts. Most nominations are uncontroversial and win easy approval. But the threat of defeating nominees may influence the names that the president sends to the Hill. And confirmation hearings not only enable senators to judge the nominees' qualifications but let them send messages to the administration. See Leahy ask Mukasey about torture.
• Appropriations. Lawmakers may use earmarks and limitations are to direct and restrict the availability of funds for specified activities. Look here for a map of some earmarks. As with nominations, they may also use hearings to raise policy questions. See Obey ask Secretary Gates about Gitmo.
• Investigations. Congressional committees often conduct investigations and oversight hearings. One famous example was the Senate Watergate Committee, in which then-staffer Fred Thompson played a role. Congress may also study executive branch operations through the GAO, the CBO, and the CRS.
• Legislation. Of course, Congress may influence the executive by passing laws requiring or forbidding certain activities. As the readings point out, the Supreme Court ruled against the "legislative veto."

Congress seldom resorts to a more powerful weapon: impeachment. See the cases of Johnson, Nixon, and Clinton.

In curbing the executive, how successful has Congress been? Under which circumstances does which branch have the upper hand?