A new Quinnipiac poll shows Donald Trump and Hillary Clinton tied at 47 percent in a head-to-head race in Colorado. When Libertarian and Green Party candidates are added into the mix, Trump is down just 2 points (44 percent to 42 percent). That's a big swing from Quinnipiac's last poll of Colorado in August when Clinton led Trump by 10 points (49 percent to 39 percent).

The tightening, according to Quinnipiac, is mostly due to shifts among white college-educated voters: In August, Clinton had a 25-point lead among that group (58 percent to 33 percent) but now leads Trump by just 5 points (45 percent to 40 percent).

Trump has increased his margin over Clinton among white voters without college degrees from 17 points in August to 23 points in September. Clinton's margin over Trump among non-white voters is steady: It was a 35 points in August (64 percent to 29 percent) in August and is 38 points in September (62 percen to 24 percent).

Quinnipiac is of course just one pollster, and other polls out of Colorado have recently painted a contradictory picture: Emerson College found Trump leading Clinton by 4 points last week, but a PBS poll relased today showed Clinton up by 9 points.

If Trump were to win all the states where he currently holds any lead in the Real Clear Politics average of polls, he would still need to secure one more state to win a majority of Electoral College votes. Clinton now holds significant 5- to 6-point leads in the polling averages for New Hampshire, Pennsylvania, and Virginia. It's entirely possible that Colorado could end up putting one candidate or the other over the top in November.

Correction: This article originally reported that a Franklin and Marshall poll released today also showed Clinton leading; Franklin and Marshall participated in conducting the aforementioned PBS poll.

Plausible Electoral College results in light of new polling: Trump 275, Clinton 263 pic.twitter.com/Szlv3fDLWF — John McCormack (@McCormackJohn) September 22, 2016