Worst

What are the worst Supreme Court decisions in the history of the country?

Scott v. Sanford, which upheld African American slavery?

Plessy v. Ferguson, which established the separate-but-equal doctrine?

Korematsu v. U.S., which OK'd internment camps for citizens of Japanese ancestry?

Bowers v. Hardwick, which approved the criminalization of sex between consenting adults?

Bush v. Gore, which usurped both voters' and states' rights to elect a President?

Tough to say.  But to these undistinguished examples of jurisprudence, John McCain would add Boumediene v. Bush, the recently-decided case that upheld Guantanamo detainees' right to habeas corpus:

John McCain weighed in on the U.S. Supreme Court decision on the rights of Guantanamo Bay prisoners to challenge their detention in U.S. courts at a town hall meeting Friday, calling the 5-4 decision “one of the worst decisions in the history of this country.”

Consider that for a moment.  This decision, which gives people who were scooped up by the military in the confusing wake of the ouster of the Taliban regime in Afghanistan the chance to be heard by a court and to challenge their summary designation as "enemy combatants."  It gives these people access to The Great Writ, the  legal procedure that has been the very cornerstone of Anglo-American civil liberties for the last 700 years.

To John McCain, though, that prospect is worse than permitting slavery, worse than racial separation, worse than interning people in camps based on their ancestry, worse than governmental intrusion into people's most intimate personal lives, worse than having a court pick a President.  That's how much the possibility that just maybe, in some cases, the government accidentally picked up innocent men along with the guilty, seems to derange him.

Wow.