If memory serves me correct, Nixon went after his boss Ike used the CIA to pull off a few controversial operations in the region. Nixon's trip was as a member of the then current administration, not the presumptive nominee of the opposition party.

Nixon also had quite the successful trip to Beijing while President opening up relations with China and therefore bringing Brezhnev to the table for a little detente.

You're kind of comparing apples and oranges here. Both men have completely different styles. I wonder if elected Obama could use a charm offensive to directly address the Iranian people (who genuinely like us from what I understand). However, I do hope that if elected Obama has half of Nixon's ability to play pragmatic hardballl when necessary.