Presidential election polls have swung like an open door during this campaign season and that's likely to continue, according to polling expert Nate Silver.

In a FiveThirtyEight story, Silver — the founder and editor-in-chief of the ESPN-owned website — argues that the Electoral College might not save Democrat Hillary Clinton from losing to Republican Donald Trump.

Trump has made up ground on Clinton in most polls, although Clinton still has a nearly 75 percent chance of winning the presidency. But in this election, nothing is guaranteed.

"But what if the race continues to tighten? I've often heard Democrats express a belief that Clinton's position in the swing states will protect her in the Electoral College even if the race draws to a dead heat overall," Silver writes.

"But this is potentially mistaken. Although it's plausible that Clinton's superior field operation will eventually pay dividends, so far her swing state results have ebbed and flowed with her national numbers."

An analysis this week, however, predicted Clinton will keep several blue states painted blue en route to defeating Trump by a margin similar to that of 2008 and 2012.

Silver, who correctly predicted the winner of the 2008 presidential election in all but one state and went perfect in 2012, said states like New Hampshire have been too "swingy" to make an accurate call at the moment.

"Overall, Clinton's leads in the tipping-point states — the ones most likely to determine the Electoral College winner in a close election — average about 4 percentage points, close to her numbers in national polls," Silver writes.

"With a tighter race, the model's expectations for Clinton are lower. A new poll showing her up by 5 or 6 points in Florida or Ohio — which would have been a ho-hum result a few weeks ago — could be a terrific one for her today, depending on the pollster."

Clinton leads Trump in the majority of polls, but a new survey from Rasmussen Reports shows Trump with a 1-point advantage, 40 percent to 39 percent.

The results from a Fox News poll released this week, meanwhile, show the race between Trump and Clinton is a statistical tie.