In 1987, Congress fixed the triggering mechanism and restored the sequester in Gramm-Rudman II.

WSJ: Phil Gramm: Obama and the Sequester Scare

As they have consistently, Republicans, especially in the House, adamantly refuse to include balance in the triggering mechanism.

WHITEHOUSE: The White House

In July 1986, Congress had the opportunity simply to stop the sequester after the Supreme Court invalidated its triggering mechanism.

WSJ: Phil Gramm: Obama and the Sequester Scare

Officials said a circuit board and battery pack - parts of a triggering mechanism - had been recovered and the lid of a pressure cooker, apparently blown off during the explosion, was found on the roof of a nearby building.

BBC: Boston Marathon 'bombing suspect' seen on video