Why do the leftists jump to extremes so quickly?

One example I can think of is immigration. At this point almost every sub where immigration is brought up it’s straight to Holocaust comparisons after someone shares an ICE raid article.

Another one is birthright citizenship debate going straight to revoking citizenship of Slave decedents and Native Americans.

I’m just confused since these seem like pretty logical actions being taken and all of a sudden we’re back to Nazis and Slavery.