Congress has the power to subpoena citizens to offer testimony. The government bases this authority on Congress’ legislative duties. Creating just laws requires accurate information. Congress can elicit this information from people when needed. Nevertheless, in a nation that prizes and guards its freedoms, the United States places limitations upon this power to compel testimony.

Contempt of Congress

Congress can issue contempt citations to people unwilling to provide testimony, within certain limits. Congress can ask the Justice Department to incarcerate any witness impeding an investigation. In the case of Anderson v. Dunn (1821), the Supreme Court upheld the right of Congress to have people arrested for contempt. This right has its limitations. Congress must demonstrate that the testimony of the prospective witness would aid its ability to create laws. If not, then the contempt citation is invalid.

Fifth Amendment

The Fifth Amendment to the Constitution further limits Congress' ability to call for testimony. American citizens have the right under the Fifth Amendment not to testify when doing so would cause them to incriminate themselves. Thus, a person called to testify before Congress can refuse if they believe the government could use the testimony against them in criminal proceedings. To render the protections against self-incrimination ineffective, Congress can provide immunity from criminal prosecution. If granted immunity, a witness cannot seek protection under the Fifth Amendment.

Juries

Juries can refuse to convict persons charged with contempt of Congress. To convict a citizen for failing to testify before Congress, the U.S. Department of Justice must convince a jury of guilt. Over the years, juries have refused to convict fellow Americans. Usually, this occurrence is a sign that the public finds the criminal prosecution unfair. A prime example of jury nullification came during the House Un-American Activities Committee investigation of supposed communists in the 1950s and 1960s. Out of the hundreds charged with contempt, the Justice Department could only win convictions in nine cases.

Executive Privilege

Executive privilege is one of the most effective limitations on the Congressional power to compel testimony. Since the Constitution considers all branches of the federal government equal, presidents claim the privilege to refuse to provide testimony to Congress. Nevertheless, the federal courts generally uphold the right to subpoena executive branch officials. The problem for Congress is that it is difficult to punish members of the executive branch for non-compliance. Except for Congress’ power to impeach, neither branch has the constitutional authority to punish the other. The Department of Justice has traditionally refused to prosecute these officials for contempt of Congress.