From the piece:
Despite Reagan’s claim that he made a deal with the Democrats, the Senate at the time was controlled by Republicans. Sen. Bob Dole of Kansas — then chairman of the Finance Committee and later the majority leader and Republican nominee for president — was a driving force behind a big tax increase because he was concerned about soaring deficits after Reagan had boosted defense spending and slashed taxes.
Dole warned the White House that the final year of Reagan’s three-year tax cut was at risk unless revenue could be raised in other ways. Under Dole’s leadership, the Senate Finance Committee led the way in crafting a big tax bill, fending off efforts by Democrats to halt Reagan’s tax cut.
Key people on Reagan’s team — especially budget director David Stockman and White House Chief of Staff James A. Baker III — were eager to rein in the deficit. But others, such a Treasury Secretary Donald Regan, were skeptical of a deal. Regan, in his memoir “For the Record,” proudly notes that he demanded a ratio of $1 in tax increases for $3 in spending cuts.
Stockman, in an interview, acknowledged that “we needed a 3-to-1 ratio to get the deal accepted by Reagan and the Adam Smith tie boys (e.g. Ed Meese, et al).” But it appears that Reagan and Regan did not actually understand the mechanics of the agreement. It turns out that much of the savings were not from spending cuts — and many of the savings were dependent on actions by the Reagan administration.