"Third parties have an enormously difficult task that they have to face," Norman Provizer, a political science professor at Metropolitan State University, said.
To qualify for participation the Commission on Presidential Debates requires candidates to meet three standards. The candidate must be constitutionally eligible. They must be on the ballot; and they must receive at least 15 percent support in five national polls. It is the latter requirement that few third party candidates qualify under.
Third party candidates are nothing new in American politics.
"Since 1832 there've been third party candidates on the ballot for president," Provizer said.
In that time the most successful candidacy was that of Theodore Roosevelt in 1912.
Roosevelt, who had earlier been elected to president running as a Republican, ran on the Progressive Party ticket. He received 27.4 percent of the vote. William Howard Taft, the Republican candidate, got only 23.2 percent of the vote. By splitting the votes, Democrat Woodrow Wilson was elected with 41.8 percent of the vote.
"If there's a third party candidate in the race, the first question everyone asks is, which of the major party candidates is that third party candidate taking votes from?" Provizer said.
Dr. Jill Stein is running for President this year on the Green Party ticket. The Massachusetts mother, housewife and physician is running because she doesn't believe either of the two major party candidates are offering solutions to this country's problems. She has developed what she is calling "The Four Pillars of the Green New Deal."
Read the details of the plan
Stein is frustrated with not being included in the presidential debate process.
"These are solutions that are within our reach right now, if we the people have a voice," Stein said. "It is the American people who are locked out of this election."
While Stein will not be participating in the presidential debate at the University of Denver, she will be involved in alternative event. Stein and Justice Party candidate Rocky Anderson will participate in a live streaming debate in which they will respond to statements made by President Obama and Governor Romney.
The third party debate will be streamed live.
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