Ok...So If he manages to win enough GOP to overturn Nixon's nomination in '60...who would he choose as his running mate...If Oswald still has his way in TTL, and Rockerfeller is assasinated,,,Ford maybe as VP? And with Brooke could we have him in Reagan both reach an agreement in 76 to run in 80 with Reagan at the top of the ticket and Brooke as VP...Let's just say John Hinckley is a lil more successfull in his attempt in 81 and we have the first Black President
Rockefeller means no Goldwater means no Reagan speech means no Governor Reagan… etc.
I think Oswald is butterflied. He got lucky as is, and there's no certainty he would even have wanted to kill Rockefeller.
Rockefeller's VP… he needs a solid conservative, preferably from the Midwest, West or Border South. At the time it would have been traditional to go with a Senator, one not up for re-election. I'm sure that list is only a couple names long.
Rockefeller probably has two terms, barring a Cuban Missile Crisis starting WWIII, and may or may not get involved in Viet Nam (Henry Kissinger was a long-time advisor of Rockefeller before joining the Nixon administration).
So he leaves in '68 and his VP is defeated by a Democrat with appeal to northern blacks which, coupled with the South, is enough to win. ATL 1968 is probably not as crazy as OTL '68—I can see the whole Civil Rights / Viet Nam War blowing up in the public's conscious being delayed a couple years.
That leaves the Republican Party in a teetering position. Rockefeller won on the Northern black/urban vote, but the Democratic South is falling apart as liberal and conservative Dems go at it. IOTL of course the Republicans choose the Southern Strategy. In the ATL they choose to sacrifice the South and put Brooke on the '72 ticket as the VP.
I'm not sure who the '72 Republican President is… a successful Mayor Lindsay? Probably a little too much combined with a black VP. Hmm. Whoever the Governor of California is? Perhaps Reagan, perhaps somebody else. A major Senator or Governor from the West or Midwest is probably required.
Anyway the Republicans take back the Presidency in '72, Civil Rights explodes and the President is killed for some reason or other, Brooke becomes President.
That's my stab at it, anyway.