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The author of the below article reckons:
The parallels to today are easy to see.
Whatever one thinks of the stands Donald Trump has taken on the issues, they have resonated strongly with a large enough fraction of the GOP primary and caucus electorate to make him the presumptive nominee. Establishment candidates are not united, and GOP orthodoxy has proved to have too little appeal.
Like Willkie, Trump has run as an insurgent populist, challenging the elitist wing of the GOP that has long dominated the nominating process.
And like Willkie, Trump will find winning enthusiastic support from Republicans who supported establishment candidates very difficult, because they denounced him as an unqualified interloper during the primaries and caucuses.
Neither the Willkie nor the Trump candidacies has destroyed the GOP, but both disrupted it. The consequences were lasting 76 years ago, and I would predict they will be so this time around also.
In Willkie’s case, his nomination helped reorient the GOP away from a strongly anti-New Deal position to one that accommodated the most popular New Deal stands on matters foreign and domestic, such as support for Social Security and aid to Britain during World War II.
Trump appears to be doing something similar, in the sense that his nomination will likely push the GOP to do more to improve life for working- and lower-middle-class Americans, who have seen their quality of life decline in important ways over the past generation.
More on the rise of Willkie here.