O'Neill was invited to the Oval Office by Nixon and Kissinger, and clerked for Rehnquist; he's no "political independent".
From the Houston Chronicle:
In a series of memos, Nixon aide Colson, who later went to prison for his role in the Watergate scandal, referred to the administration's efforts to promote O'Neill and to challenge Kerry to debate him.
<snip>
Colson wrote that he arranged an Oval Office meeting between Nixon and O'Neill on June 16, to boost the morale of O'Neill, who had become disillusioned because of the hostile reception he received during other television appearances.
O'Neill, who had flown up from his hometown of San Antonio, spent about 40 minutes chatting with Nixon and National Security Adviser Henry Kissinger about the war and its opponents.
Nixon said he understood that O'Neill was "the guy to take brickbats when you go on some of these TV shows." He encouraged the young veteran to continue his fight.
"Give it to 'em. Give it to 'em. You can do it," said Nixon, according to a tape of the meeting.
<snip>
The next day Colson wrote a memo to top Nixon aide H.R. Haldeman, pronouncing the session a success:
"O'Neill went out charging like a tiger, has agreed that he will appear anytime, anywhere that we program him and was last seen walking up West Executive Avenue mumbling to himself that he had just been with the most magnificent man he had ever met in his life."
http://www.chron.com/cs/CDA/ssistory.mpl/front/2476454Anyone who'd call Nixon "the most magnificent man he had ever met in his life" obviously has a few screws loose.