My guess is if Rockerfella won the California Primary a compromise would run as the Republican
This is certainly possible, but there is a rebuttal: "Goldwater had 883 votes out of 1308 on the first ballot. California had only 86 votes. Even if Goldwater lost CA, he still has 140 delegates to spare. CA was a narrow win for Goldwater, a narrow loss is not going to scare a horde of informally pledged delegates and make them bolt to other candidates. 1/5 of the OTL Goldwater votes have to bolt to deny him the majority. The California primary was late, and most of the delegates were already chosen."
My rebuttal to the rebuttal:
"I am not certain about that, for this reason: Once it is clear that a candidate is going to win the nomination, he gets a *lot* of votes from people who were not hard-core supporters. He gets people who were only mildly leaning toward him and some who were genuinely undecided or even opposed but who figured that there is no point bucking the inevitable.
"I do not think it implausible that there were at least 140 delegates who voted for Goldwater who might have been dissuaded from doing so. Goldwater himself said in an ABC television interview on May 14 that there would be "four hundred and twenty-five" hard-core delegates--he was assuming a victory in the California primary--who "will stay right to the end and march out the back of the convention if they don't get what they want. That is how hard these people are." (Quoted in George Gilder and Bruce Chapman, *The Party That Lost Its Head* [1966], p. 196; an interesting look at 1964 from a liberal Republican perspective--yes, George Gilder was a liberal Republican in those days!...) Gilder and Chapman note that "450 delegates, no matter how militant, cannot win a convention, and Goldwater at the end had some 400 more." They were for the most part ordinary Republicans, on the conservative side, but not ideological zealots. The California primary was important not only for the delegates it directly brought Goldwater but for the way it persuaded such Republicans that Goldwater was in the mainstream and might actually win. If Goldwater had lost in California--a little more than two weeks after finishing *third* in Oregon--such delegates might have stopped to ask themselves: If he can't win Republican primaries in the West, just where, outside the South and perhaps a few die-hard Rocky Mountain and Great Plains states, *can* he win in November?
'Also, a Goldwater defeat in California might have led both Eisenhower and Nixon to have taken a harder anti-Goldwater line than in OTL, and this would probably have had some influence on wavering delegates. Furthermore, IIRC there were a couple of "favorite sons" (Governor James Rhodes in Ohio? Congressman John W. Byrnes in Wisconsin?) who withdrew, and who, if they had stayed in the race, might have helped to deprive Goldwater of a first-ballot victory..."
https://groups.google.com/d/msg/soc.history.what-if/Ghzn1YByCDA/ww4p3unAnz8J