The raise of right-wing populist movements does not explain lower birthrates

There is a hypothesis discussed around here that claims that the raise of right-wing populist movements is what causing the population decline. I'm not saying that the raise of right-wing ideas should not be a concern, but this post is about evidence that it is unlikely that that is what is causing fewer births overall. This post does not embrace or attack any political idea.

There is also the problem of causality. For instance, the raise of right-wing movements may actually be a response to smaller younger populations, since younger people usually be Left-wing. If this is the case, then population decline will actually affect left wing movements more.

In any case, you have to take in mind that many political and activist movements (right, left and center) love to use our social and demographic problems to justify pushing their own ideas. So far the population decline is extremely diverse, ranging from religious Iran in the Middle East to Japan and secular Nordic countries.

Some facts that contradict the claim that the raise of right-wing movements is causing population decline:

• Liberal and Left-Wing couples are less likely to have kids overall. Source.
• Republicans are more likely to be married (67%) than Democrats (45%) or Independents (52%) (Pew, 2010).
• More liberal Countries have tried giving more benefits to mothers and couples with kids, which probably would ease gender roles, but that also failed to raise birth rates. Source.
• Women did not significantly vote more left wing than in other elections for the past decades. Source.