There has always been a special place in my heart for Nynorsk, the form of written Norwegian that looks distinctively Norwegian and not like any other language. It seems like Nynorsk should be the left-wing variety of Norwegian, but in practice it does not appear that municipalities that officially use Nynorsk show any particular tendency to vote for the left.
In any case, it strikes me as a mild injustice that abroad we have Bokmål names of political parties presented to us as though they are the definitive Norwegian names. I decided to look at the name in each register of each party in the Storting. Parties with differing names are bolded.
Nynorsk is a rather irrelevant minority language used by less than 10% of the adult population, so it's natural to perceive Bokmål as Norwegian. It's almost exclusively used in rural Western Norway and some mountain valleys in the interior, which are not exactly leftist strongholds, for obvious reasons. Many municipalities are officially neutral when it comes to the written form used, but the vast majority of people in these places use Bokmål.
All the population growth is in the cities and immigrants naturally pick Bokmål, so while the numbers of Nynorsk users is fairly stable their share of the population is declining. The main function of Nynorsk in the cities is being used by some middle class people to avoid getting their kids put into classes with "too many" ethnic minority children (Irish in Ireland and Swedish in Finland are used in a similar way by similar types).
I'm not a Nynorsk user myself, but I have to comment on this, as it's quite a stretch. I've only ever heard of
one case perhaps fitting this description, decades ago, at the local primary school where I live in Oslo. And even then, the idea that this was the real motivation was very much disputed. Your post makes it seem like this happens a lot, which would be very difficult anyway - there are hardly anyone who uses Nynorsk as their primary language at primary school level in the major cities. (In 2016/17 there were in only three - 3 - such pupils in all of Oslo and Akershus.)
