It depends on how things turn out for RFK. If he manages a negotiated end to the war in Vietnam and ramps up the War on Poverty, combined with Nixon's reforms (OSHA, EPA), and a possible universal health insurance system, RFK probably wins a second term and exits the White House in 1977 with a moderately high approval rating. Inflation and white blacklash, however, are probably not far behind.
After that, you probably have a moderate Republican take the White House in 1976 (not so sure that someone like Reagan could have jumped directly into power without a fellow Republican like Nixon to help lay the groundwork). Probably not Gerald Ford. My money would be on Charles Mathias of Maryland or George H.W. Bush with a comparably conservative running mate. Deregulation and interest rate cutting begins, and our incumbent probably goes on to win a second term in 1980 over someone like Henry Jackson.
The oil shock probably means that, however, our incumbent probably only barely scrapes by to a second term. This, combined with high unemployment in the early eighties means that the Democrats probably expand their majorities in the House and Senate in 1982. By the time 1984 rolls around, the Republicans disavow their moderate wing and a conservative is chosen for the top of the ticket (Bob Dole? Phil Crane?). The youngest Kennedy throws his hat in the ring with RFK's support, and clears the primary field.
With the incumbent relatively unpopular, Kennedy probably beats Dole or Crane handily, becoming the third Kennedy to take the White House. Teddy pushes for expanding health coverage beyond what it already has been established as (maybe to cover dental care or orthodontal care), and creates work programs to combat unemployment. The economy evens out, and Teddy is given part of the credit, but he becomes quickly hampered by increasing deficits, piled up by his brother and our moderate Republican.
In 1988, EMK wins a second term, though with a much smaller mandate than he got in 1984. Deficit reduction becomes the key focus on EMK's second administration, which he conducts by raising taxes and cutting military spending. Not sure that we see a recession in the late eighties (Deregulation not on the Reagan scale, of course), but at any rate, the American public is probably getting tired of the Democrats and the Kennedys by the time 1992 rolls around.
As for 1992...Republican President Ross Perot?
