“I will always put America first,” Donald Trump told the UN General Assembly last month. The president assuredly has, at least in the sense of consistently advocating for his America First agenda as outlined on the campaign trail. The policies he proposed then were a jolt to the foreign policy establishment and to America’s longstanding role in the world. Yet on trade, alliances, immigration and international agreements, Mr Trump again and again found support from his campaign audiences. The question now is whether that support is growing or shrinking.

A core contingent of Trump supporters remains steadfast behind the president, according to newly released polling by the Chicago Council on Global Affairs. Americans with a “very favourable” view of the president also endorse the individual priorities of his America First agenda. For example, eight out of 10 core Trump supporters consider immigration a “critical threat”. Six in 10 endorse withholding the US security guarantee to allies who fail to spend enough on defence, as the president has suggested.

Yet, support among all Americans is lower for America First policies this year than it was last year. Instead, a strong majority continues to favour the more internationalist policies pursued by Mr Trump’s predecessors over the past many decades.