The answer is really simple, money. Murtha is the picture of rampant Washington pork barrel politics. Think of the hundreds of millions (probably billions) that the bureaucracies could spend on a "terrorist prison" with all the bells and whistles.
"Sure, I'd take 'em," said Murtha, an outspoken critic of the Iraq war. "They're no more dangerous in my district than in Guantanamo."
Yes Jack, and they would be little turban wearing cash cows for your district for years and years.
Whenever you ask yourself why one of these insane liberals does anything, just follow the money.