https://ash.harvard.edu/articles/the-real-numbers-tracking-crowd-sizes-at-presidential-rallies/
So far in 2024, CCC has logged 37 political rallies at which former president Donald Trump appeared, and we have information on crowd size for 28 of them. Across those 28 rallies and using our standard estimation rules (see below), the average crowd size has been about 5,600. That’s similar to averages of 4,600 in 2023 (19 events with information on crowd size)
Since late July, when she became the presumptive and then official Democratic Party nominee for president, Vice President Harris has appeared at six campaign rallies. The reported crowd sizes at those rallies have ranged from about 10,000 to about 15,000, and we calculate an average size across the six of about 13,400.