We had another nativist victory in Austria earlier in the week, where their nativist Freedom Party's candidate came in first in the presidential election; he'll face a Green foe in the run-off, as the main center-right and center-left parties came up short.
The linked piece does a Q&A with an Austrian poli-sci prof, who makes this assessment along the way-
One factor behind the Freedom Party’s success is its status as an opposition party. It has attracted voters who aim to punish the current government for its performance. Without much government turnover, long-term party loyalties have frayed. For example, most blue-collar workers abandoned the Social Democrats and are now voting for the Freedom Party, making it, in effect, the new labor party.
The last German state elections had the same effect, where the nativist AfD was drawing votes from the left-of-center parties more than the center-right Christian Democrats.
There are some interesting applications for US politics. If The Donald does get the nomination, there might well be some blue-collar voters who are not social liberals who might warm to Trump. He's not an economic conservative despite being a billionaire, so he is less vulnerable to having the tool-of-big-business card played on him, especially when Hillary Clinton has just as many, if not more, corporate friends.
Where Trump resonates is with, as I've discussed before, blue-collar traditionalists
Blue-collar traditionalists don't have a natural home in either party. The usual mix of pro-business policies and social conservationism don't resonate overly well, but plays to patriotism and traditional culture do, especially when multiculturalism and hostility to traditional values become coins of the realm.
Since Trump hasn't tacked to the right on economics, he can have a shot at reaching some traditional Democratic voters in the general election. A more protectionist trade policy would help folks in manufacturing jobs that don't compete well with imports, and his immigration hawk persona will appeal to blue-collar Anglos, including some old-school blacks.
Blue-collar whites have become less and less of a Democratic strong suit in the last few decades. If a Republican can speak to the fears of globalism, secularism and open borders but not induce the fears of the safety net being scrapped, they could turn the US' main party of the right into "the new labor party" as well.