After convincing victories in Tuesday's primaries in five East Coast states, Trump has roughly 10.1 million votes, about 200,000 more than Mitt Romney got during the entire 2012 primary campaign.

And with the primaries ahead — including in populous states such as California, New Jersey and Indiana — the former "Apprentice" ­reality TV star should easily break the modern record of 10.8 million held by George W. Bush in 2000, according to blogger Eric Ostermeier, a political science professor at the University of Minnesota.

"In an election cycle with a high Republican turnout, his numbers are rising, even more so now that there's only three candidates" left in the GOP race, he said.

The reasons include a combination of Trump's celebrity, media exposure and higher-than-usual interest in his over-the-top candidacy, Ostermeier said.

The numbers-crunching blogger uses figures compiled by Congressional Quarterly that differ from those compiled by other groups, some of which say Bush got as many as 12 million votes in the 2000 primaries.