I don't see that the article is praising Duke, but rather analyzing his performance in the election. On several occasions the article notes Duke's "baggage" and "taint" and suggests that a future candidate who doesn't have that baggage and taint but has the same platform could succeed.
Put another way, the article can be summarized as "A candidate who wasn't a racist who ran on a platform of lower taxes, no welfare, etc. could win." How is that "praise" for Duke?
I guess you missed the part where he cheered ‘scaring the blazes out of the establishment’ and saying he made good sense?