It's probably just the fact that Republicans are by and large centrist liberals. You have to be far from the centre on either side to develop a strong friend-enemy distinction.

Democrats are way further Left-wing (especially on sociocultural issues) than Republicans are Right-wing. Thus they are more likely to see Republicans as hostis (collective enemies) whereas Republicans find it more difficult to see Democrats as hostis in turn. Almost everything about Republicans—whether free-market dogmatism, rampant consumerism, racial 'colourblindness', atomized individualism—is clearly part of the liberal centre where people like Macron openly sit. Macron would be a 'Blue Dog' 'corporate' Democrat at Leftmost or 'RINO' at Rightmost if viewed from an American lens. And it is also where most of the Western 'Right-wing' sit as well.

After all, most Western countries, including Britain, Germany and the USA, have no sizeable Right-wing. For example, Merkel calls herself a 'centrist', and referred to her party using the German words for 'The Centre' rather than 'The Right'. Theresa May also stressed 'governing from the centre' and opposing 'narrow nationalism'. All this indicates that May and Merkel were centrist leaders of historically Right-wing parties. We see the same thing happening with Valerie Pecresse in France—another centrist who is dragging her historically Gaullist Right-wing party Leftward.

It's the same thing in America with Trumpian populism being distanced from anything genuinely Right-wing. We should keep in mind that Trump was easily the most Left-wing of Republican Presidents (the first pro-fag Republican President, for example). The whole 'Caitlyn' Trans-Jenner for Governor farce proved that the Republican Party is by and large also pro-trans enough to stand them as candidates in 2021. Republicans are simply liberals occupying the positions that actual paleoconservatives, ethnonationalists, etc. would occupy were it not for America's inherent Left-bias (the unfortunate consequence of being founded by the radical revolutionaries of their time and never developing a genuine, counter-revolutionary Right-wing).