Here is Humphrey’s 1968 convention speech. That man will beat Reagan? I love Humphrey, dude was usually right and usually principled but it’s not like he was some exciting candidate in 1968.
Think about what 1968 looked like at the time. RFK & MLK have been assassinated. The Dem convention is melting down, if they can’t run a party how can they run a country? Tons of white people hate civil rights and certainly didn’t approve of MLK before his death. Here comes Ronald Reagan to say we’re going to end the war with honour—not like those liberal hippie peaceniks—because I’ll use Nixon’s secret plan! (or whatever) and by the way I love black people (North), I hate black people (South) and just like OTL the British journalists writing the ATL An American Melodrama will notice the details like radio ads in Southern markets while American journalists miss it entirely. He’ll talk about being an FDR Democrat (wink you know when white people got all the benefits wink) and talk about how important unions are because he ran one in collusion with MCA, he’ll duck Medicare by slamming Medicaid because old white seniors matter more than poor people, etc. Reagan is not some young inexperienced dude in 1968, supply-side doesn’t exist so he’ll run on JFK style tax cuts I suspect (and that’ll be popular), he’ll be Law & Order with Roger Ailes sliding in to run media.
Unlike Goldwater Reagan isn’t going to constantly talk about his crazy ideas (well okay he totally did haha, but I don’t think Humphrey can execute well) because he’s an actor—the first with a million dollar contract courtesy of Lew Wasserman’s MCA—and knows his lines… except that time he dropped his cards in 1980 and didn’t remember the order lol. The Dem base will not turn out for Humphrey, he’s not hip enough and RFK is dead and McCarthy lost. Nor does Humphrey have the killer instinct that say LBJ could have used to beat Reagan—and isn’t that a fun possible timeline!
But yes, all of this needs Wallace out of the picture because really racist voters want to hear the whole shebang not just the coded messages. No Wallace means they’ll settle for the wink and nod routine of Reagan.
Edit: I almost forget but one under mentioned detail about the ‘68 election was that the Democratic Party was flat broke, out of money to a comic degree. Reagan and Hollywood money is going to make things even worse than Nixon’s lopsided advantage OTL—25.4 million to 11.6 million or adjusted 2018 dollars of 183.6 to 83.9 million.
This NYTimes article from 1971 goes into some detail about all the extra spending past that.