The number is expected to surpass the record set in 2008.
Sharpton is also speaking with Hillary Clinton the same day.
The demonstrator was mocking Rubio's repetition at Saturday's debate.
The super-PAC hired the agency that coordinated President Obama's African-American paid media.
The accidental online post was made before voting has ended.
"If we don't have a border, we don't have a country," he added.
"That means you’re doing something right,” Rubio said.
"I always have to remind people that this is really early in the process," he added.
"It was a great moment," Trump added of his supporter's words.
“In a certain way, evil,” Trump responded when Clinton’s name appeared.