Of course, it is more likely for the Republican Party to talk like it's moving into that territory, but not actually do anything. But, for example, Trump's emphasis on "America over trade" is something that could actually help workers.
A typical conservative would say something like: what do you call the boss of a small window cleaning firm? Is he a capitalist or a member of the working class? The left generally ignore questions like this because they can't answer them. But they do spend lots of time trying to tell everyone that society is simple and "conservatives" are one big blob that all hate "workers".
Generally conservatives are anti-union, because historically unions have been very tied up with communism, very aggressive/violent and very anti-competitive, all of which are antithetical to what libertarian conservatives believe yield the most socially beneficial outcomes. That is, they're anti union because they think unions are in fact worse for the "working classes" - to the extent such a concept makes sense at all - than not having them.
No one in this subthread is talking about the millions of Republican voters out there. The people being talked about is the much smaller group of people who set Republican policy. And we don't need to read their minds; we can look at their policy platform and directly witness what they support.
But they don't really mean it and have never meant it. The Republican party, at least in modern history, has never been pro working class in any real sense. The opposite in fact, probably far more hostile to working class than Democrats.
Much of the "pro working class" rhetoric is largely just conservative values like abortion or region. Maybe a better way to phrase it is "pro rural white conservative working class values".