1. Anti communists are always on the defensive, making compromises with the Marxists. You will never see the marxists doing this. The Russian Tsar did this and he ended up dead because of it., and just like today the marxists never stop pushing their agenda. You can't negotiate with people who want you dead. You give them an inch, they take 20 miles.
2. Propaganda, the anti communists underestimate the power of it. You need to understand how to reach neutral people instead of creating echo chambers. Also the marxists are much better at organized propaganda campaigns and understand how important it is.
3. Lack of organization. One thing I see repeating over and over is the anti communists always seem to be atomized, and believe just because they're the "silent majority" theres no way they can lose. It only takes 3.5% of the population to overthrow a country, the white russian army lost due to infighting despite being better trained soldiers than the bolsheviks.
4. Marxists are willing to do anything to win, whether it be cheating, stealing etc. Most anti communists cant comprehend that some people will sink that low, this past year is a good example. They will never tell you they're marxists, they use subversion to win over otherwise apolitical people as well as poor people who are mostly ignorant of political ideologies.
5. Anti communists cave to words like 'anti semitism" and "racism" then immediately go on the defensive trying to appeal to the marxists by going off how not racist they are etc. This doesnt work, they really don't care about that they only care about your political ideology. Saying things like " the marxists are the REAL racists" does absolutely nothing. They dont care and that wont change anyones mind.