His writings are extremely relevant because they are what the leftists are studying at the high school and college level.
LOL. You are assuming that high school students GIVE a rat's patootie about history. All high school girls think about is their HAIR. All high school boys think about is sex.
College students might get all hot and bothered about Marx but they VERY soon get over it and him when they enter the REAL WORLD of work, commute, work, work, commute, home, food, T.V. and then MORE work.
I taught at the college level for 27 years. Let them spout and sputter. It will be a pleasant time for them to remember while they are on their daily three-hour commute to/from work.