Boring speaker, lackluster campaigner very vulnerable to the carpetbagger charge. Former drug industry lobbyist (wife still is!) and not a native son. (Very important in Appalachia! Unless you have lots of money!) Manchin’s campaign constantly played the native son card. Had WV sports legends cut commercials for example Jerry West & Don Nehlen. I didn’t see a single commercial saying what Manchin has accomplished as a senator. That’s because he had no accomplishments!
Given that Morrisey broke the Dem lock on the AG office, which hadn’t elected a Republican last since 1928, and was the only Republican to win statewide that year, he seemed the best shot to take on Manchin (at a time when Manchin was faring poorly in the polls and seemed to just be utterly disinterested in whether he wanted to stay Senator or come back and run for Governor again).
The native son thing never struck me as particularly important, given that they elected the carpetbagger Rockefeller and North Carolina White trash Cornelius Calvin Sale, Jr., to the Senate.