Nixon had a better resume, but he just couldn't seem to catch a break. For starters, the country happened to be in a recession, and then Eisenhower offered only lukewarm support. Actually, lukewarm is too strong a word. Eisenhower would have needed to heat it up to get to lukewarm. When asked what ideas Nixon had contributed to the president, Eisenhower said, "If you give me a week, I might think of one."
The supposed "turning point" was the televised debates when a stubbly-faced, pale Nixon went up against John F Kennedy. 1
But the real turning point was election night itself. In spite of the lopsided electoral vote, Kennedy won the popular vote by less than one tenth of one percent. Republicans cried foul, saying Kennedy had benefited from widespread fraud in Chicago and Texas. (Had Nixon won these two, he would have carried the electoral college.)
For example, the patriots in little Fanin County in Texas, with only 4,895 registered voters, cast over 6,000 votes. Chicago Mayor Daley, whose political machine routinely delivered whopping victories to Democrats held back a lot of the Chicago vote until the morning of November 9th.
When the votes were "counted" - a lot of the ballots seem to have disappeared - Kennedy had won Chicago with a ten-percent margin, overcoming Nixon's victory in the rest of the state. Although things smelled fishy, subsequent reports said it didn't smell of an entire tuna, which would have been enough to say the election was actually stolen. In a recount, the only state that went to Nixon from Kennedy was Hawaii.
Result
John Kennedy: 303
Richard Nixon: 219
1. The F stood for "Freaking Beefcake."