
Why has the (US) Democratic Party always been more europhilic than the (US) Republican Party?
It's weird but this is in noway a new phenomenon. Indeed, it has been going on since the Antebellum era. The Southern Democrats were really obsessed with English romantic and chivalric literature, especially the works of Walter Scott. They even portrayed themselves as the true Anglo-Saxon/Norman civilization of America.
Meanwhile, the Republicans only cared about England in so far as if she may intervene in their Civil War. They didn't even look up to England's abolitionism.
This continued towards the World Wars where the Democrats were far more supportive of intervention in Europe. Woodrow Wilson's foreign policy explicitly sought to make the United States a participant in European affairs and to construct a system of international collective security.
However, the Republicans would stop that from happening and even refused to join the League of Nations, an organization that an American president had created.
The Second World War also continued the pattern but to a lesser extent as both Democrats and Republicans generally favored supporting the United Kingdom matireally, and were both hostile to the Nazis even before the war unlike the Kaiser.
Even during the Cold War where both parties were extremely internationalist and America was far more concerned with Asia, the Democrats still managed to edge out by having a more international tone while the Republicans favored an Americentric one.
This is weird since both parties viewed the European democracies as brother countries but the main difference was what they emphasized. The Democrats emphasized them as well as human rights and stuff to boot while the Republicans mainly talked about just America as the last bastion of freedom.