(Adds Supreme Court ruling, critics)
By Bill Trott
March 20 (Reuters) - Fred Phelps, the pastor who led a small Kansas church's vitriolic "God Hates Fags" anti-gay campaign across the United States, has died, the church said on Thursday.
Phelps, whose Westboro Baptist Church in Topeka, Kansas, won a 2011 freedom-of-speech U.S. Supreme Court decision related to their anti-gay picketing, died on Wednesday in a Kansas hospice at the age of 84.
"People die - that is the way of all flesh," a blog post on the church's website said.
Phelps founded the church in the 1950s.
In his later years, Phelps, known as "Gramps" to his family, turned over much of the church's day-to-day operations to his offspring.
In March, his son Nathan, who ran away from home as soon as he turned 18 and later became a gay rights advocate, said in a Facebook posting he had learned Phelps was near death in a hospice and that he had been excommunicated in 2013. The church would not confirm the excommunication report, saying membership issues were private.
Phelps' church was widely denounced as a hate group and was not part of any mainstream Baptist organization. Its membership has been estimated at about 100, many of whom were related to Phelps.
By Phelps' reasoning, cancer, the Sept. 11, 2001, attacks on the United States, school shootings and the deaths of soldiers in Afghanistan and Iraq, as well as other tragedies involving Americans, were God's retribution for a lax attitude toward what he called "the modern militant homosexual movement".
"God Hates Fags" was the overriding slogan for Phelps and his followers, as well as the name of their primary website. They carried that message to protests, brandishing signs declaring "Thank God For AIDS," "America Is Doomed," "Thank God For Dead Soldiers" and "God Blew Up The Troops".
"Look, you can't preach the Bible without preaching the hatred of God," Phelps said in a 2010 Huffington Post interview.
The news of his death was met with an outpouring of comments on social media, including many who said Phelps' teachings inadvertently served to promote tolerance.
"I'd like to thank Fred Phelps today, for accidentally inspiring me and countless others like me to fight for tolerance and against hate," Russell Hainline, a screenwriter in Los Angeles, tweeted.
Phelps' rhetoric was hotter than fire and brimstone. He called President George W. Bush a "Bible pervert," Barack Obama a "bloody beast" and conservative TV commentator Bill O'Reilly a "demon-possessed messenger of Satan".
Phelps's church gained notoriety in 1998 by picketing the funeral of Matthew Shepard, a gay man who was beaten outside a bar in Wyoming and left to die. His story was turned into a movie and play.
SUPREME COURT RULING
Phelps and his congregants had their biggest impact at military funerals, where they faced an angry backlash from veterans' families and their supporters. Their right to picket led to action by the U.S. Congress and a freedom-of-speech legal battle that the church won at the U.S. Supreme Court.
The father of a Maryland soldier killed in Iraq took on Westboro, seeking damages and saying church members had turned his son's 2006 funeral into a circus. But in an 8-1 ruling in 2011, the court said that even though the Westboro protest was hurtful, it was constitutionally protected. Phelps' daughter, Margie, argued the case.
To curb Westboro, Congress in 2006 passed the Fallen Heroes Act, which prohibited protesters from coming within 300 feet (91 meters) of a federally administered cemetery within an hour of the beginning or end of a funeral. States passed similar laws.
Phelps based his ideology on an Old Testament passage - the book of Leviticus, chapter 18, verse 22 - that says, "Thou shalt not lie with mankind as with womankind; it is abomination."
On its website the church claimed to have held almost 50,000 demonstrations since 1991.
Westboro would send protesters on the thinnest of premises. A store in Topeka was a regular target because it sold vacuum cleaners made in Sweden, where a preacher had been prosecuted for his anti-homosexuality message
Phelps's church even sent a contingent to Pittsburgh in 2003 for the funeral of Fred Rogers, the mild-mannered host of the children's TV show "Mister Rogers Neighborhood," on the grounds that he was "a wuss" and had not denounced homosexuality.
Other protest targets included churches and synagogues, rock concerts, NFL games, Twitter headquarters and the school attended by President Barack Obama's daughters.
British journalist Louis Theroux lived with the Phelps clan for three weeks while making the 2007 documentary "The Most Hated Family in America".
"The dominant note in his personality was a bitter contempt for humanity in general and me specifically," he wrote in the Guardian newspaper.
Theroux said the family did not always seem hateful.
"Away from the pickets, they were - much of the time - very, very normal," he said. "Not just normal, but intelligent and urbane. They're not hillbillies, they're urban professionals."
(Additional reporting by Victoria Cavaliere in New York; Editing by Gunna Dickson and Stephen Powell)