WASHINGTON • Republican Donald Trump, after weeks of self-inflicted damage, has seen support for his candidacy in national polls dip into the 30s - Barry Goldwater and Walter Mondale territory - while Democrat Hillary Clinton has extended her lead to double digits in several crucial swing states.
Time to declare a landslide, right? Not so fast. The vote may be more favourable to Mr Trump than the worst-case-scenario prognosticators suggest for a very simple reason: Landslides do not really happen in presidential elections any more.
It has been 32 years since a president won the popular vote by a double-digit percentage. That was when Mr Mondale suffered an 18-point defeat to Mr Ronald Reagan in 1984. It was also the last time there was a landslide among states, with Mr Mondale winning only Minnesota and the District of Columbia.
There are a variety of factors that are likely to prevent a candidate today from rallying the huge, 60-plus-point majorities that swept Mr Franklin Roosevelt into office in 1936, Mr Lyndon Johnson in 1964 and Mr Richard Nixon in 1972.
The United States is too fragmented and its political temperature too overheated for any single person to emerge as a consensus choice for anything nearing two-thirds of the electorate.
And that climate has led the political parties to become far more ideologically uniform than they used to be. "The biggest difference between today and say, 1936 or 1964, is the composition of the two parties," said Mr Jonathan Darman, author of the book Landslide: LBJ And Ronald Reagan At The Dawn Of A New America.
Party identification used to be more fluid, making it less difficult for partisan voters to conceive of supporting someone of the opposite affiliation. "The Republican and Democratic parties were much more heterogeneous than the parties we have today," Mr Darman said. "Party identification had a lot more to do with regional ties and family traditions than ideology."
Data shows just how less likely crossover voting is today. Ninety per cent of Republicans and two-thirds of independents see Mrs Clinton unfavourably, according to the most recent McClatchy/Marist poll.
And many Trump defectors are choosing to vote for third-party candidates, which has also contributed to Mrs Clinton's inability to break the 50 per cent threshold in most national polls.
According to Ms Amy Mitchell, director of journalism research at Pew Research Centre, about 20 per cent of voters now hold political beliefs that place them at the ideological poles of their respective parties - a number that doubled from 2004 to 2014. And these people tend to reinforce one another's views.
"Those on the ends of the political spectrum are more likely to surround themselves with people that think like they do," Ms Mitchell said.
This high level of polarisation could contribute to a curious electoral phenomenon, which could cost Mrs Clinton support: If people begin to believe that she is going to run away with the election, they may lodge a protest vote against her simply to deny her a commanding victory.
The margin of victory is about more than just bragging rights.
"A mandate is some kind of issue platform that you have advocated that is the basis of your victory," said Mr Lee Miringoff, director of the Marist Institute for Public Opinion.
"Not fear of the person who got beaten, which I think is the prime motivator of the Clinton people: the fear of Trump. The same thing can be said for Trump voters: fear of Clinton."
NEW YORK TIMES