This was the second of two elections in the 20th century in which Ohio, a historical bellwether state, voted for the losing candidate, the first being 1944 when Republican nominee Thomas E. Dewey carried the state over President Franklin D. Roosevelt. It would not do so again until it backed Donald Trump over Joe Biden in 2020.[1]
This anomaly was due to strong anti-Catholic voting (amidst an overall nationwide pro-Democratic swing) in the Appalachia-influenced, heavily Baptist southern and western parts of the state.[2] This was also the last time until 2020 that Ottawa County voted for the losing candidate. Had Kennedy won the state along with Roosevelt in 1944, Ohio would have had the longest streak of any state voting for the winning candidate up until 2020.
Ohio was one of the largest states to hold a primary, with 64 delegates to the DNC.[4] Its primary, held on May 3, coincided with that of neighboring Indiana.[4]
Kennedy had campaigned in Ohio numerous times in the two years prior to announcing his official candidacy.[4] While his internal polling was positive, it also showed that he could still lose if a strong candidate launched a favorite son campaign against him.[4] His campaign team was particularly worried about Frank Lausche launching such a challenge.[4] In November 1959 their polling showed a race between him and Kennedy resulting in a statistical tie.[4] Those polls showed that Kennedy would win the race a race between him and DiSalle 62 to 38%.[4]
Kennedy felt that he could not compete in both Ohio and Wisconsin due to time limitations preventing him from being able to spend adequate time in both states.[4] Kennedy saw Wisconsin as providing him an opportunity to potentially deliver an early and fatal blow to Hubert Humphrey's campaign.[4] Thus, he chose to compete there instead of in Ohio.[4]
Kennedy felt that he needed to secure DiSalle's endorsement ahead of declaring his candidacy in order to demonstrate appeal outside of New England.[4] Thus, in December 1959, Kennedy and DiSalle brokered an agreement in which DiSalle would run as a favorite son committed to Kennedy, and would endorse Kennedy and announce his intention to run as a favorite son to assist his candidacy in a January 6 press announcement, four days after Kennedy's formal announcement of his candidacy.[4]