1950 to 1983: built, then trimmed with care
The triumph of 1950. Congress extends coverage to the self-employed and to farm and domestic workers, and raises benefits. Rural members of Congress now have constituents with a stake. Social Security passes Old Age Assistance during the decade.
The ritual. Actuaries assumed wages would stay level. Wages rose, so the system kept showing surpluses, and Congress kept spending them:
"In this manner, a regular ritual developed after 1950 of raising benefits in election years." (p. 265)
Democrats held Congress "for all but two years" between 1949 and 1981 and took the credit. Program administrators helped: they "took deliberate steps to remove some of the program's political liabilities."
1972. A 20 percent increase, and automatic cost-of-living adjustments starting in 1975. Nixon and other Republicans "welcomed indexation."
1983. Indexing met the inflation of the 1970s and the system ran short. A bipartisan commission, then a deal between Reagan and Speaker Tip O'Neill, roughly half revenue and half cuts: benefits partly taxable, the cost-of-living adjustment delayed six months, the retirement age raised from 65 to 67, phased in over decades.
Nobody's check went down. The retirement age rose on people who were in their twenties. That is Pierson's traceability, used on purpose.