but seems you question was about apples and oranges.
Ok. A valid point.
Allow me to compare apples and apples.
Take a Democratic Party Rally, and a Republican Rally. Why is the protocol different between those two ?
Trump did not keep protesters out. He threw out those who abused the opportunity and tried to shut down his rally. Those who were disturbing the peace, interfering with a government controlled (SS) function, and those who attempted assault on a Presidential Candidate.
Here is how the democrats treat protesters , who had not committed any of those crimes.