Popularism can have overlap (Venn diagram style) with conservatism (small 'c') but won't get close to 1:1 anytime soon
It's more likely that they will part ways and never overlap at all, because popularism is closest to a 49/51 democracy, which devolves into socialism (or results from, even). In other words, the overlap is a fleeting moment when people agree on direction, not on destination.