There is evidence that many Republicans are coming around to support Donald Trump's candidacy, and more of them need to "come home," Republican National Committee spokesman Sean Spicer said Tuesday.

"The stakes are too high," Spicer said on Fox News' "America's Newsroom," agreeing with Trump's running mate Indiana Gov. Mike Pence's call on Monday for Republicans to support the GOP nominee.

"There are too many things at stake domestically, foreign policy, Supreme Court picks," Spicer said. "Republicans have to understand that there are only two choices in this race, Hillary Clinton or Donald Trump. The federal judiciary itself is enough of a reason to understand that contrast. We will change the trajectory of this country for a generation and beyond if we don't make the right choice."

There are still some who are not on board yet, he admitted, but there is "continued growth" occurring, which could lead to the 270 Electoral College votes Trump will need to win the White House.

Early voting, though, may not be enough, as Democrats are the voters who usually cast their ballots before Election Day, while Republicans are more likely to wait to cast their votes.

"In Florida, we have a lead when it comes to absentee ballots requested and returned," Spicer said. "We are up total of 850,000 from 2012, [and] Democrats are down. You go to Iowa, in the last five days we have led the number of absentee ballots returned. Democrats are down about 82,000."

He also mentioned other states, including North Carolina and Nevada, where Republican absentee ballots are higher on the GOP side.

But same day ballots matter, too, said Spicer.

"In North Carolina alone, Barack Obama had a 300,000 early vote lead going into Election Day, and Mitt Romney carried that state because Republicans showed up on Election Day," Spicer said. "So if we can cut into the early vote of Democrats in some of these key battleground states, that portends well for us on Election Day."