Mark Cuban. Justin Sullivan/Getty Images Brash billionaire Mark Cuban argued on Wednesday that polls would not be a good indicator of the 2016 election outcome.

"This election will be determined by the battle of science vs anger," the owner of the NBA's Dallas Mavericks and star of ABC's "Shark Tank" tweeted. "Ground game vs the draw of the angry voter. Polls won't tell the story."

Trump, the Republican nominee, has watched as his standing in national polls, as well as in crucial swing states, has crumbled after a series of missteps following the Democratic National Convention in late July.

But polls are known to fluctuate throughout the campaign cycle and aren't necessarily predictive of what could happen in November.>

Cuban recently endorsed Democratic nominee Hillary Clinton at a rally in Pittsburgh, his hometown. He called Trump a "jagoff" — a popular, demeaning slang term frequently used in western Pennsylvania — during the event.

Earlier in the cycle, Cuban expressed interest in serving as either Trump's or Clinton's running mate before souring on the Manhattan billionaire's candidacy.