In the 1980 presidential election:
Ronald Reagan 50.7 %
Jimmy Carter 41.0 %
John Anderson 6.6 %
http://www.presidency.ucsb.edu/showelection.php?year=1980
Now, 41% is a substantial defeat for an incumbent president. But is 51% for Reagan a landslide ? ? But it was sure often portrayed that way, in large part because it translated to such a big electoral college victory.
So, another interesting POD . . .
Hubert Humphrey stays in the Senate during the Reagan years:
Such big economic factors leading to the decline of middle-class jobs, I'm not sure one more voice would make that much of a difference. And with Reagan supporting the military regimes in El Salvador and Guatemala, and the right-wing rebel army in Nicaragua, I think he was as mistaken as can be. But in a sense, such policies were over-determined. Ever since the Cold War started in 1945, we pretty much propped up every military dictatorship we could find, as long as they could mouth the words they were anti-communists. And this was both Democratic and Republican administrations. And following the Iranian hostage crisis, there was a lot of currency to being 'touch.' And so, Humphrey being one more voice, no matter how well he can distill down the issue, no matter what kind of down home examples he can use, no matter what facts he can accurately point to, not sure it would make that much of a difference.
Okay, so what effect might Hubert have:
(1) Maybe the Tax Reform Act of 1986, which had at least some bipartisan support, such as Democratic Senator Bill Bradley who advocated the view of fewer loopholes, lower rates. Maybe it could be a bigger improvement.
(2) And Immigration Reform, I think around '86(?), too. Maybe it could have just worked much better, or maybe that's expecting the man to be too prescient, too influential. But let's take a flight of fancy and suppose it does.