Is there any proof for this statement? Republicans want cheap labor, they'll tell you that themselves, but I don't believe the Democrats would ever say that they believe in labor immigration to "get more voters".
That just sounds like a ludicrous conspiracy.
"Demographics is destiny" seems to be a quote from a french philosopher from the 1800s, while "coalition of the ascendant" seems to be a description of the coalition Obama sought to build in his second term, an idea swiftly dismantled in 2016.
The articles I can find discussing these things don't contain any democrats scheming about using immigrants to overtake the republicans. The only people I find talking about how it will "estrange the republican party from these growing demographics" are republicans. I'm not going to claim that no democrat has ever considered that outcome, but I am going to propose that it seems more likely to me that if that were to happen it would be a result of politics they'd be in favor of anyway.
In general, it's pretty popular to help people. I don't think republicans would disagree that part of their coalition is built on higher income individuals, which they hope to grow by raising incomes. They're not doing that as a sort of underhanded tactic, they believe income is good. In the same way I think the Obama democrats do believe in helping immigrants, and obviously that makes them more popular amongst immigrants. That's not a scheme, that's just a policy.
I don't think this is nearly as clear cut as you believe it is.
But what was the nature of "the coalition Obama sought to build in his second term?" Normally, political coalitions are based on things like geography or economic classes. But Obama's coalition was based on ethnic groups. Specifically, it was based on winning supermajorities among demographic groups that were rapidly growing due to immigration. Indeed, the results of the 2016 election were portrayed in U.S. media as being the last gasp of the old America before it was washed away by demographic change.
Respectfully, maybe this would be clearer to you if you lived here, and spent the last 15 years reading countless headlines and articles about demographics, which were relatively rare before 2008. And those headlines and articles suddenly stopped last November, when Donald Trump won a narrow majority of naturalized citizens. None of that is a coincidence.
> The articles I can find discussing these things don't contain any democrats scheming about using immigrants to overtake the republicans... I don't think republicans would disagree that part of their coalition is built on higher income individuals, which they hope to grow by raising incomes.
That's a good comparison. But I think it's totally fair to say that Republicans have a policy of giving tax cuts to rich people because it inures to their political benefit. Republicans obviously never say that in those words, but Democrats certainly characterize Republicans that way. And I think it's a fair criticism.