And some people think this is a recent development.

I mean, I don't doubt that they were thinking of this. But the country was quite isolationist, and truth be known, up until about GWB, the GOP was fairly isolationist in terms of military action (No more nation building!). And there was a fair amount of resistance generally to getting involved in "another foreign war". Even Joseph Kennedy was opposed to helping Britain and favored dealing with Hitler.

From Wikipedia:

Kennedy also argued strongly against providing military and economic aid to the United Kingdom. "Democracy is finished in England. It may be here," he stated in the Boston Sunday Globe of November 10, 1940. With German troops having overrun Poland, Denmark, Norway, Belgium, the Netherlands, Luxembourg, and France, and with daily bombings on Great Britain, Kennedy unambiguously and repeatedly stated his belief that this war was not about saving democracy from National Socialism (Nazism) or from Fascism. In an interview with two newspaper journalists, Louis M. Lyons, of The Boston Globe, and Ralph Coghlan, of the St. Louis Post-Dispatch, Kennedy said:

It's all a question of what we do with the next six months. The whole reason for aiding England is to give us time ... As long as she is in there, we have time to prepare. It isn't that [Britain is] fighting for democracy. That's the bunk. She's fighting for self-preservation, just as we will if it comes to us..... I know more about the European situation than anybody else, and it's up to me to see that the country gets it.[5]

His views were becoming inconsistent and increasingly isolationist; British MP Josiah Wedgwood, 1st Baron Wedgwood, who had himself opposed the British Government's earlier appeasement policy, said of Kennedy:

We have a rich man, untrained in diplomacy, unlearned in history and politics, who is a great publicity seeker and who apparently is ambitious to be the first Catholic president of the U.S.[39]

In British government circles during the Blitz, Kennedy was widely disparaged as a defeatist. He retreated to the countryside during the bombings of London by German aircraft, at a time when the British Royal Family, Prime Minister, government ministers, and other ambassadors chose to stay in London. (This prompted a member of Britain's Foreign Office to say, "I thought my daffodils were yellow until I met Joe Kennedy.&quot

When the White House read his quotes it became clear that Kennedy was completely out of step with Roosevelt's policies. Kennedy returned home. Roosevelt urgently needed his support to hold the Catholic vote and invited him to spend the night at the White House. Kennedy agreed to make a nationwide radio speech to advocate Roosevelt's reelection. Roosevelt was pleased with the speech because, Nasaw says, it successfully "rallied reluctant Irish Catholic voters to his side, buttressed his claims that he was not going to take the nation into war, and emphasized that he alone had the experience to lead the nation in these difficult times." After Roosevelt was reelected, Kennedy submitted his resignation as ambassador

that opposed helping England. It was mostly either Republicans and/or large corporations that opposed intervention

Probably depends upon whether you are discussing national politicians, or Americans in general.

Public-opinion polls of the time also show considerable support for mandatory neutrality measures as a means of keeping the nation out of wars abroad. A large and vocal isolationist bloc in Congress, composed of both Republicans and Democrats, supported this legislation, and many were strongly in favor of provisions that limited presidential discretion. Newspapers, particularly those of the Hearst chain and the influential Chicago Tribune, along with many periodicals, such as New Republic and The Saturday Evening Post, gave support to neutrality legislation. Peace societies, many women’s organizations, and some religious groups also supported mandatory neutrality provisions and the embargo of arms sales. As late as 1939, sentiment against participation in a European war was so strong that President Franklin D. Roosevelt’s attempt to gain revision of the neutrality laws in the first session of the Seventy-sixth Congress was a failure. Only after war came to Europe in September 1939 were changes in the neutrality laws that allowed for the sale of arms on a “cash-and-carry” basis finally made. Until then the isolationists in the United States prevented the country from playing a concrete role that might have prevented the outbreak of war.

Still the GOP had political reasons for wanting to get rid of FDR. They thought Hoover was right about how to hand the Depression. The would have just tried trickle down economic and not done anything like FDR did. They vehemently apposed the New Deal and would have abolished it.

And they would have never helped Britain no matter what. And Hitler would have won.

An awful lot changed after Pearl Harbor. I'm not sure even the GOP could have held back FDR after that.

It would have been interesting to know if they would have supported a Marshall plan under different circumstances though.

Which is not the same as "wanting to help Hitler."

Goalposts are made to stay in one place, not to validate our narratives...

or anyone like him