בס''ד
In the 1960 Presidential election, Kennedy had to convince Americans to elect the first Catholic. This was a serious issue then. America was majority Protestant and many Protestants feared having a Catholic in the White House.
So Kennedy went to Texas to deliver a famous speech to Protestant ministers. In his speech, he sought to prove that he is no puppet of the Vatican by stating that he disagrees with the Church's pro-life position. Kennedy was pro-abortion in 1960 at a time when Americans were majority pro-life.
One other point. Kennedy's positions in the 1960s do not seem left-wing by today's standards. Because he could not get away with adopting positions further to the left. But if he lived in today's world, I believe that he would adopt more left-wing positions just as his entire family has done.
For example, when Kennedy was president, all the psychiatric and psychological associations defined homosexuality as a mental illness. Homosexual acts were a crime in all 50 states. Even in left-wing New York, dancing with another man was a crime. A man dressing like a woman was a crime. It was illegal for a restaurant to serve a homosexual. There were homosexual bars but they were constantly raided by the police, and all of the patrons were arrested. The few tiny homosexual organizations that existed also agreed that homosexuality was a mental illness because they did not want it to be defined as a criminal offense. Homosexuals then swore that they would never seek the right to marry.
In the 1972 Presidential election, the Democrat candidate George McGovern was considered a radical for suggesting that homosexual acts between consenting adults be decriminalized. President Nixon defeated McGovern in 49 out of the 50 states.
That should give us some idea of how different this country was 50 years ago.