As Elena Kagan is witnessing first-hand, it's a time-honored tradition for critics to undermine a Supreme Court nominee by drawing unflattering comparisons to failed nominees of the past. Kagan, a former Harvard Law dean, generally enjoys broad support and seems likely to be confirmed as President Obama intends — unlike these five ill-starred judicial hopefuls, to whom, in some cases, she's already being compared:

1. "My Little Crony"
Who: Harriet Miers, nominated by George W. Bush in 2005
Why was she a disaster? The nomination of Miers, a close friend of the Bush family, prompted charges of cronyism from Democrats and Republicans alike. She had never acted as a judge, and Senators said she gave "incomplete to insulting" written answers to their questions about her Constitutional views. The negative perceptions of Miers crystallized in a widely circulated cartoon portraying her as Bush's wide-eyed toy — a "my little crony."
What happened next: After three weeks, Bush withdrew his nomination. Miers resigned as White House counsel in 2007.

2. The highest judge in the land
Who: Douglas Ginsburg, nominated by Ronald Reagan in 1987
Why was he a disaster? The U.S. Court of Appeals judge withdrew himself from consideration after media reports revealed he'd smoked marijuana with his students during his stint as a Harvard Law School professor.  
What happened next: Ginsburg's pot-smoking past led several politicians — including Al Gore and Newt Gingrich — to come clean about youthful drug use. Ginsburg remains a judge on the D.C. Circuit Court.

3. The racist rookie
Who: G. Harrold Carswell, nominated by Richard Nixon in 1970
Why was he a disaster?
The Senate rejected Nixon's choice primarily on the grounds of inexperience — but Carswell's record of "vigorous belief in the priniciples of White Supremacy" certainly didn't help. Attempting to marshall a defense for the nominee, GOP Senator Roman Hruska tried to put a positive spin on Carswell's self-evident shortcomings: "There are a lot of mediocre judges and people and lawyers," he said. "They are entitled to a little representation, aren't they?"
What happened next: Carswell's career ended in scandal. After an unsuccessful attempt to enter politics, he was arrested and convicted of battery in 1976 for making advances on an undercover cop in a Florida men's room. 

4. A sex-crazed sexagenarian
Who: Lucius Q.C. Lamar, nominated by Grover Cleveland in 1887
Why was he a disaster? Critics charged that Lamar, the first former-Confederate nominee, was much too old for the job (he was 62, at a time when U.S. life expectancy was less than 50). He was also dogged by accusations of sexual misconduct, including the charge that he gave a woman a government job in exchange for sex. 
What happened next: In today's world, Lamar wouldn't have stood a chance — but, under 19th century norms, he was confirmed for the job, and served for five years as an associate justice before his death in 1893.

5. The three-time loser
Who: Reuben H. Walworth, nominated by John Tyler on three separate occasions in 1844
Why was it a disaster? "The Senate reacted with disdain" to Tyler's three-time choice, never once granting Walworth a proper hearing. Tyler, who assumed office after William Henry Harrison's death and enjoyed almost no political support in Congress, finally gave up.
What happened next: Walworth's luck didn't improve — he soon lost his job as chancellor of New York, and failed to win election as governor of the state in 1848. Consolation prize: Wisconsin named a county after him.