One of the first Republican members of Congress to express concerns about President Richard Nixon's role in the Watergate scandal, Weicker developed a reputation as a "Rockefeller Republican", eventually leading conservative activists to endorse his opponent Joe Lieberman, a New Democrat, in the 1988 Senate election which he subsequently lost.

"[12] Weicker voted in favor of the bill establishing Martin Luther King Jr. Day as a federal holiday and the Civil Rights Restoration Act of 1987 (as well as to override President Reagan's veto).

"[16] Weicker's political career appeared to be over after his 1988 defeat, and he became a professor at the George Washington University Law School.

[27] Connecticut politics had a tradition at the time of opposition to a state income tax—one had been implemented in 1971 but rescinded after six weeks under public pressure.

[28][16] Weicker initially campaigned on a platform of solving Connecticut's fiscal crisis without implementing an income tax.

The Los Angeles Times wrote that support from Democrats was credited for Weicker's victory, reflected in Morrison's third-place finish.

[11] After taking office, with a projected $2.4 billion deficit,[29][27] Weicker reversed himself and pushed for the adoption of an income tax, a move that was very unpopular.

"[30] Weicker vetoed three budgets that did not contain an income tax, and forced a partial government shutdown, before the General Assembly narrowly passed it in 1991.

[32] However, he earned national attention for his leadership on the issue, receiving the John F. Kennedy Library Foundation's Profile in Courage Award for taking an unpopular stand, then holding firm.

"[23][12] Despite his increasing popularity, he did not seek re-election as governor in 1994, citing wanting to spend time with his children as the reason.

His last year in office was marked by a controversy over the firing of the state commissioner of motor vehicles, Louis Goldberg.

He expressed sympathy for the budget struggles of Governor Dannel Malloy, drawing a parallel with his own efforts to remedy a fiscal crisis.

[23][12] In his book Independent Nation (2004), political analyst John Avlon describes Weicker as a radical centrist governor and thinker.

[36] Despite the long professional relationship, Weicker did not support former WWE CEO Linda McMahon in either of her unsuccessful bids for the U.S. Senate in 2010 or 2012.

[40] In 2015, despite criticizing Cuba for its lack of "human rights and democratic elections", Weicker described the country's free healthcare system as one of its most positive aspects.

[24] His third marriage, to Claudia Testa Ingram, lasted from 1984 until Weicker's death, at Middlesex Hospital in Middletown, Connecticut, on June 28, 2023, at age 92.