I don't know Prescott Bush well but I imagine it affects him. Whether or not it'd pull him out of or push him deeper into politics I have no idea.
That said, a lot of people will focus on issues about the presidency, but it goes deeper. Bush was RNC Chairman, a CIA Director, and a Chinese Ambassador in the '70's and there'll be profound effects there, especially on the first one - a different chairman could frame Nixon's scandals better or worse, stand by him shorter or longer.
Obviously, Reagan picks a different running mate, and we likely have a different president from 1989 to 1993, and from 2001 until 2009, but everyone's gonna say that