A high number of voters are still looking for an alternative to Donald Trump and Hillary Clinton, and a sizeable chunk of them are considering Libertarian Party nominee Gary Johnson, according to a poll released Friday.

Johnson, formerly a Republican governor of New Mexico, pulled 8 percent of the vote poll by Rasmussen Reports, which included him in a three-way match-up with Clinton and Trump, the likely Democratic and Republican nominees.

Johnson's support appears to come almost entirely from the 24 percent of voters who have said they did not plan to vote for either Clinton or Trump in this and previous versions of Rasmussen's daily tracking survey.

Friday's poll, which includes interviews conducted Tuesday and Wednesday, shows Clinton with 39 percent compared to Trump's 37 percent, with 12 percent saying they planned to vote for someone other than the three candidates listed and 4 percent who said they were undecided.

"It is becoming clear at this early stage of the campaign that both Clinton and Trump are having trouble drawing more voters into their camps, particularly those not affiliated with either major party," Rasmussen said in a press release. "This is feeding interest in third-party candidates like Johnson who was chosen last weekend as the Libertarian Party's presidential standard-bearer."

But five months ahead of the election, , there's no evidence Johnson is pulling support away from either of the likely major party nominees.

Clinton's support was unchanged from Rasmussen's Thursday poll, which did not include Johnson. Trump's support ticked down slightly – down one point, from 38 percent – overnight, well within the survey's 3-point margin of error.

Of the 18 percent of those who said Thursday they would vote for someone other than Trump or Clinton, a little less than a third said they would choose Johnson. Many of the rest are likely those who say they plan to write in the name of Clinton's Democratic presidential rival, Vermont Sen. Bernie Sanders, or Jill Stein, who is expected to be the Green Party's nominee.

Sixty-six percent of Democrats say they support Clinton, compared to 15 percent who prefer another candidate, likely a reflection of the lingering battle between the former secretary of state and Sanders, who trails her by an almost insurmountable number of delegates but won't drop out of the race. Trump, meanwhile, has consolidated 75 percent of the Republican vote.

Dissatisfaction with Trump and Clinton – who, respectively, have the highest and second-highest unfavorables ever measured for major-party nominees – has candidates like Johnson and Stein hoping to disrupt the Democratic and Republican parties' iron grip on the nation's politics.

But history shows people tend to tell pollsters they plan to support an independent candidate, but ultimately vote for one of the major party nominees or stay home on Election Day.

In the months leading up to the 2012 election, Johnson, who was also the Libertarian Party nominee that year, polled around 5 percent in a match-up with President Barack Obama and Massachusetts Gov. Mitt Romney. He ultimately got just shy of 1 percent of the vote.

Johnson and his running mate, former Massachusetts Gov. Bill Weld, say that could change if they are invited to debate Trump and Clinton during the fall campaign.

"If we get in the debates and show well, the polls show that between 40 and 55% of the American public agrees with our sense of the issues," Weld said in an interview on Fox Business Network Wednesday. "What we're up against is a duopoly, the entrenched position of the two parties – they're not going to go quietly."