Donald Trump is beating Hillary Clinton in the polls in key battleground states among voters who want change, a possible roadblock in her bid for the presidency, CBS News elections director Anthony Salvanto said Sunday.

A recent CBS poll depicted a very tight race in battleground states, such as Florida, Colorado, and Wisconsin:

Hillary Clinton holds narrow leads over Donald Trump across a number of key states of Florida (up three points, 44 to 41 percent); Colorado (Clinton 40 percent, Trump 39 percent); Wisconsin (Clinton up 41 percent to 36 percent) and North Carolina, which has flipped back and forth between the parties in the last two elections, where it's Clinton 44 percent and Trump 42 percent.

The article further pointed out that opposition voters could be a reason the polls are so close.

And much of the vote appears locked in already: the bulk of those not voting for Clinton say they will not consider her, and the bulk of those not voting for Trump say they will not consider him. In Florida, sizable numbers of voters are voting in opposition to a candidate they don't like: Forty-eight percent of Trump's voters are backing him mainly to oppose Hillary Clinton, and 32 percent of Clinton's voters are with Clinton in order to oppose Trump.

Salvanto explained that even though Clinton is leading slightly in those states in the polls, this does not necessarily mean that Clinton is in the clear.

"Yeah, well, she's leading, but at the same time, she has to watch a couple of things," he said. "One is that Donald Trump continues to own the issue of change. More people in these states say he can bring change."

He then stated that Trump has a strong base of voters, but has not yet gathered enough voters to "propel him" to a victory.

"Now, he's limited to some extent, because the voters we talked about, the ones who feel like they're not at ease with globalization, et cetera, there is enough of them to keep him where he is but not yet to propel him to a win," he said. "So, if they start to look more for change for change's sake, then I think we could see the needle move a little bit."