Dennis Webster DeConcini (/ˌdiːkənˈsiːni/; born May 8, 1937) is an American lawyer, philanthropist, politician and former U.S. senator from Arizona.

The DeConcini amendment, which establishes the use of US military force in Panama, is written and signed by Omar Torrijos in the Instrument of Ratification, but it is alleged that it does not exist.

Asked if the fact that the Church amendment is part of the Panama Canal Treaty, which ends next December, is a reason for it not to have effect on the Neutrality Treaty, which does not end on that date, and which has no termination date, López Guevara responded that "it doesn't matter because it is part of that negotiation."

DeConcini was widely noted as a member of the Keating Five in a banking and political contribution ethics investigation during the 1980s which grew out of the U.S. Savings and Loan Crisis.

The Senate investigation involved Charles Keating and Lincoln Savings/Continental Homes, the sixth largest employer in the state of Arizona at the time.

[6][7] In the 101st Congress, DeConcini served on the Senate Appropriations Committee, chairing the Subcommittee on Treasury, Postal Service and General Government.

[9][10][11] In February 1995 DeConcini was appointed by President Bill Clinton to the board of directors of the Federal Home Loan Mortgage Corporation (Freddie Mac), where he served until May 1999.

Although he claims he has not lobbied for harsher immigration laws and sentencing practices, he admits meetings with the Arizona Department of Corrections Director Chuck Ryan and "publicly speaking in favor of" for-profit prisons.