Here are excerpts from the Democratic and Republican Platforms of 1964:
The Democratic:
Democracy of Opportunity
The Civil Rights Act of 1964 deserves and requires full observance by every American and fair, effective enforcement if there is any default.
... We will support legislation to carry forward the progress already made toward full equality of opportunity for women as well as men. We will strive to eliminate discrimination against older Americans, especially in their employment. Ending discrimination based on race, age, sex, or national origin demands not only equal opportunity but the opportunity to be equal. We are concerned not only with people's right to be free, but also with their ability to use their freedom.
Republican Platform of 1964:
Year after year, in the name of benevolence, these [Democratic] leaders have sought the enlargement of Federal power. Year after year, in the guise of concern for others, they have lavishly expended the resources of their fellow citizens. And year after year freedom, diversity and individual, local and state responsibility have given way to regimentation, conformity and subservience to central power.
We Republicans hold that a leadership so misguided weakens liberty in America and the world. We hold that the glittering enticements so invitingly proffered the people, at their own expense, will inevitably bring disillusionment and true disappointment in place of promised happiness. Such leaders are Federal extremists—impulsive in the use of national power, improvident in the management of public funds, thoughtless as to the long-term effects of their acts on individual freedom and creative, competitive enterprise. Men so recklessly disposed cannot be safely entrusted with authority over their fellow citizens.
...
3. Within our Republic the Federal Government should act only in areas where it has Constitutional authority to act, and then only in respect to proven needs where individuals and local or state governments will not or cannot adequately perform. Great power, whether governmental or private, political or economic, must be so checked, balanced and restrained and, where necessary, so dispersed as to prevent it from becoming a threat to freedom any place in the land.
If you look primarily at those institutions that were populated and run by republicans, you'll see that Jews were severely limited or even banned from those institutions.
There were strict limits set on the number of Jews allowed admission to Ivy League universities, which is one of the reasons that Jews flocked to liberal colleges like NYU. And this could also account for the hard left leaning of many Jews, when generation after generation were sent to these liberal colleges. Same with country clubs (believe it or not!). In fact, the CC fallout has continued to this day... A few years ago, Tom Watson (the PGA pro golfer from KC) was to be honored by the Kansas City Club, a very exclusive country club in KC. But he refused their offer, because it seems that they never actually removed their ban of Jews from their by-laws. It's been a number of years, so I may have some of the details wrong, but there was a huge flap over it. I believe that while Watson's not Jewish, his wife is.
Mark