Hoagland is well educated and connected AND a nut. He has done some good science. He had an article published in Nature or Science back in the 1970s prediciting liquid water on Europa due to gravitational effects on Jupiter. Turned out in the 90s that he was right. He has also long been right about the distribution of actual water (as opposed to frozen co2) on Mars.
That said, he's nutty when it comes to the Cydonia "structures" and his conspiracy theories concerning NASA.
Who says very bright people can't be loons?