DENVER – A new poll released Wednesday of nearly 1,600 registered Colorado voters found Democrat Jared Polis leads Republican Walker Stapleton by 11 percentage points in the governor’s race.

The poll from the Kaiser Family Foundation and Colorado Health Foundation was completed several weeks ago, on Sept. 18, and the surveyors polled registered voters—some who may not vote in November.

But among the 1,585 people who responded to the question, 44 percent they would support Polis, while 33 percent said they would support Stapleton.

However, 15 percent said they were undecided, 6 percent said they didn’t know or refused to answer, and 3 percent of respondents said they didn’t want to vote for either. Those figures suggest that the number of Coloradans who are still undecided could still swing the election one way or the other.

Respondents said they were overall more enthusiastic about voting in the governor’s race and congressional races this year, and 79 percent said they were “absolutely certain to vote” in the November election.

The poll’s release comes less than a month from election day and about a week after a poll done by two Colorado research firms showed Polis with a 7-point lead over Stapleton, though 11 percent of respondents to that poll were undecided as well.

It also comes as the race between Stapleton and Polis reaches a fever pitch. President Trump endorsed Stapleton in a tweet Wednesday morning, saying “his credentials and talents are impeccable” and that Stapleton had his “complete and total Endorsement.”

And on Tuesday, Sen. Bernie Sanders announced he would campaign alongside Polis in Colorado later this month during a pre-election blitz. Former President Barack Obama endorsed Polis earlier this year.

Ballots for the governor’s race are going out to registered voters in coming days. The candidates are in the midst of several debates, which will include one hosted by Denver7 and The Denver Post at the University of Denver on Oct. 23.

The poll released Wednesday also asked respondents a host of other questions relating to election issues and health care, among other things. For more on the poll, click here.