AHC: Nixon Loses Reelection

I've just had an exhausting conversation with someone who seemed annoyingly convinced Nixon losing re-election was impossible and I'd like some help in proving him wrong.

What scenarios could have prevented Nixon from getting a second term.
Early Watergate, RFK not running in 1968 but for 1972 and Nixon never withdraw from Vietnam would all cost Nixon re-election
That's what I basically had, along with some evidence of Nixon sabotaging peace in Vietnam. The person I had that frustrating conversation with kept going on about how it was unbelievable.
Nixon's 1971 request to burglarize the Brookings Institute is carried out; and the perpetrators are promptly caught, so that their trial for burglary, arson and involuntary manslaughter is ongoing during the 1972 campaign.

Liddy stoically refuses to talk, so the other defendants lawyers blame it all on him and Nixon; and someone reveals the existance of the tapes.