When it came to public policy, Donald Trump’s presidency was marked by repeated defeats when he attempted to adopt Republican orthodoxy. When he was in favor of tax cuts, the party was with him. When he insisted on massive infrastructure spending, they ignored him. Congressional Republicans are actively opposing him on several foreign policy issues, including Trump’s antagonism to NATO. Those foreign policy issues reflected Dwight Eisenhower’s enduring triumph. Republicans have always been anti-communists. But before Ike, conservatives were also isolationists, preferring that the US stay out of the world, especially long-term alliances. Harry Truman had worked with internationalist Republicans in Congress to tie the US to the United Nations, NATO, the Marshall Plan, and more, but the grassroots were not pleased and it was not at all clear where a Republican president would take over the party . Eisenhower narrowly won the Republican nomination in 1952, beating the conservative wing of a party desperate after losing five consecutive presidential elections and happy to have a war hero in charge. to the edge. His vice president, Richard Nixon, followed suit during his own presidency. Even as conservatives took full control of the party with the election of Ronald Reagan, the old isolationist impulse was reduced to occasional UN bashing. During the Cold War, there were many real foreign policy differences between the parties, but Ike’s presidency firmly placed Republicans on the side of an active continued role for the US in world affairs, including participation in a range of alliances and agreements. That dedication even survived the Cold War. When he was president, Trump didn’t care much for public order. But he undermined this internationalist consensus, even using the old slogan “America First” of an isolationist (and anti-Semitic) movement of the 1930s. And while he had little success in actually implementing his foreign policy leanings — as he was repeatedly rolled over by Congress, the bureaucracy and allied nations — it’s entirely possible he had the last laugh. Earlier this week, an astonishing 63 Republicans opposed a resolution supporting NATO. That’s still not a full third of the Republican conference, but it’s not exactly a small margin either. To be fair, some of those who objected have claimed to be against the non-binding, token resolution because of some of its specific wording rather than because they were against the alliance – but quite a few seem to be wary for the whole concept of an alliance of democracies against authoritarianism. These legislators only reflect where their party seems to be going. In two recent polls, strong Republican minorities — 40% of respondents in one survey — were in favor of leaving the alliance altogether. fairly quickly. Both sides will again be strong supporters of NATO in particular and of the general overarching direction of US foreign policy since the 1940s. But if Trump is nominated, and especially if he wins the presidency, it’s hard to see the party working as hard to curtail its foreign policy choices as it used to. What if the Democrats stay in the White House for another four years (or more)? It’s easy to imagine a partisan polarization spreading in this area, like so many others, with Republicans automatically opposing whatever Democratic presidents do — including joining the alliances that Eisenhower, Nixon, Gerald Ford, Reagan, George HW Bush, and George W. Bush all supported strongly. Preventing that outcome would require strong, responsible leadership from Republican politicians. I’m not optimistic that will happen.