To a reasonable person, yes, this should have been the case, but politics in America is far from reasonable.
The entire establishment marshaled what forces it could to stop mamdani's momentum. Couple this with the fact that there are (unfortunately) many people out there who would rather elect accused sex offenders than risk the chance that somebody marginally aligned with a word and ideology they don't actually understand (socialism) would be elected, or more likely, and worse, people are just racist and/or islamophobic and would sooner elect a man who would grope their daughter than a man who, god forbid, has a different religion than them.
The entire establishment marshaled what forces it could to stop mamdani's momentum. Couple this with the fact that there are (unfortunately) many people out there who would rather elect accused sex offenders than risk the chance that somebody marginally aligned with a word and ideology they don't actually understand (socialism) would be elected, or more likely, and worse, people are just racist and/or islamophobic and would sooner elect a man who would grope their daughter than a man who, god forbid, has a different religion than them.