Of course "Teach children positive messages and pride in their country" (which immediately brought to mind a law passed by the right-wing in France aiming at emphasizing "the positive role of colonization").
It resonates with the working classes who have had their wages held stagnant by competition from immigrants from low-income countries.
Unfortunately, no other party has even begun to address that issue so they get to collect a lot of votes.
Furthermore, the way that all of the other parties dismiss any complaints regarding immigration as "pure xenophobia" only hands them even more votes.
Which is unfortunate because they're total assholes.