(CNN) A single new justice on the tightly divided nine-member Supreme Court can change the law in America, and as past ordeals demonstrate even a failed nomination can change the course of history.

As President Donald Trump's pending nominee, Brett Kavanaugh, awaits Senate action, here are some of the more controversial Supreme Court nominations over the past five decades:

Abe Fortas, 1968. It was 50 years ago that Democratic President Lyndon B. Johnson miscalculated in his attempt to elevate Abe Fortas, then an associate justice, to chief justice. This episode began when Chief Justice Earl Warren, the architect of Brown v. Board of Education and a series of other civil rights landmarks, announced in June 1968 that he would retire. Johnson selected Fortas, who in addition to his legal credentials was a longtime friend and adviser to Johnson. Republicans and Southern Democrats banded together against him, complaining of cronyism. It was a presidential election year, which further fueled their opposition. Fortas' supporters could not overcome a filibuster, and Fortas had to withdraw. The situation then worsened for Fortas, who was accused of financial impropriety arising from side income he had collected from teaching and other connections. He left the high court altogether in May 1969. Republican Richard Nixon had won the presidency in November 1968, and he appointed conservative Warren Burger to the chief justice position.

Robert Bork, 1987. When centrist conservative Justice Lewis Powell announced his retirement in June 1987, Republican President Ronald Reagan chose Robert Bork, then a judge on a prominent US appeals court in Washington (where Kavanaugh now sits). Bork, a former Yale law professor and US solicitor general, had an extensive record as a conservative legal thinker, and Democrats, who had just reclaimed a Senate majority in the 1986 elections, mounted a fierce campaign against him. Senators rejected Bork on a vote of 58-42. Bork returned to the DC Circuit but resigned the following year, saying he wanted to speak out on public policy and against liberal activism in the courts.

Clarence Thomas, 1991. This fight has been recalled throughout the Kavanaugh episode because, like the current nominee, Thomas had appeared on a relatively smooth path to confirmation when sexually charged allegations emerged and senators were pressured to hold a second hearing. Thomas, nominated by Republican President George H.W. Bush to succeed Justice Thurgood Marshall, categorically denied the sexual harassment claims of Anita Hill, with whom he had worked at the Department of Education and the Equal Employment Opportunity Commission. Thomas had a valuable patron in respected Republican Sen. Jack Danforth of Missouri -- a former boss -- and Danforth helped him keep majority support. Thomas won confirmation on the closest vote in more than a century: 52-48. In contrast to today's intensely partisan times, Thomas won the approval of 11 Democrats, along with a majority of Republican senators.

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