From the beginning of the presidential nominating conventions in the 1830's really through the 1950's, you had conventions that actually did real business.

So if 1960 had occurred under the old convention system, Kennedy would have had a very hard time getting the Democratic nomination because he would have been rejected by all those people who had worked with him in Washington.

Oftentimes during the period in which conventions really did business, you had situations where the delegates were divided and you would have ballot after ballot before there was a final nominee.

Michael Beschloss Quotes