Carter's unpopularity and poor relations with Democratic leaders encouraged an intra-party challenge by Ted Kennedy. While Carter defeated Kennedy and secured the nomination, the fight further damaged Carter, whose popularity had been eroded by the Iran hostage crisis, and a worsening economy at home marked by high unemployment and inflation.
Reagan's campaign featured an optimistic tone as he called for an increased defense spending, implementation of supply-side economic policies, and a balanced budget. Carter portrayed Reagan as a dangerous right-wing extremist, while emphasizing his own support for liberal and progressive causes.
Reagan won in a landslide, carrying 45 of the 51 states.
As the polls closed on the East Coast, Reagan's victory was assured. Adding insult to injury for the Democrats, Carter issued his concession speech two hours before the polls had closed on the West Coast, adversely affecting down-ballot candidates in tight races. For example, the Dems' loss of the state of Jefferson's only seat in the House was at least in part due to Carter's ill-timed concession, a fact that rankled Jefferson's Democratic governor, Bill Williamson, the lieutenant governor, Al Rafferty, and state attorney general Hyman Apfelbaum.
In OTL, Reagan carried 44 out of 50 states, not 45 out of 51. Moreover, sasquatches were not a factor in the outcome, nor the long term effects.
Republican John B. Anderson ran as an Independent. He carried no states, but did capture 6.6% of the popular vote. His role in the election has largely faded from memory and is not mentioned in the story.