The rule states that in order for a candidate to be included in the debates, he or she must have at least 15% support across five national polls.
However, as the vast majority of the national polls have only included President Obama and Mr. Romney, it's essentially impossible for any other candidate to reach that 15% threshold.
In Connecticut's history, the last time a 3rd party candidate has receieved over 15% of the popular vote in a national Presidential election was back in 1992. In that year, H. Ross Perot tallied 21.58% of Connecticut's vote. However, Ross Perot was actively involved in the national debates that year.
Since the 1990s, the percentage of votes both nationwide and across Connecticut for 3rd (and other) candidates has been on the decline.
Ross Perot still managed 10.02% of Connecticut's vote in the 1996 election. Four years later, Ralph Nader was able to get 4.42% in the 2000 election. However, Nader receieved less than 1% of the vote in 2004 and he fared only slightly better in 2008, but still only tallied 1.16% of Connecticut's vote in that election.
Following Wednesday night's debate, some Connecticut votes may still be undecided. Others say that they feel like choosing one of the two leading candiates means deciding between what they call the "lesser of two evils."
There are very few large-scale polls that have included other candidates, but Libertarian candidate, Gary Johnson, has been making some minor headlines here and there. With that said, his support still remains well below 15%. Some polls suggest his support may be anywhere from near 1% to as high as almost 10% in some states. It's difficult to come up with an exact number, given the lack of large-scale polls including Johnson.
According to a 2008 press release, there were 1,925,328 registered voters in Connecticut. Of those, 802,720 were Unaffiliated, while 705,783 were Democratic. The Republican number was 410,891.
It is often said that the "swing" voters, those who are either Unaffiliated, Independent or part of another polictical party, are the ones that decide elections. With more voters registered Unaffiliated than Democratic in Connecticut, that can easily be seen.
Even aside from President Obama, Mr. Romney and Mr. Johnson, there are even other candidates. There have always been many candidates in Presidential elections, but often only the top two or possibly three get much in the way of attention.
Even for a 3rd party candidate like Gary Johnson, many people still don't know who he is. With Johnson not participating in the debates and not being included in the majority of polls, the lack of awareness of him will likely continue.
With all of this said, there will still be many that vote for him in Connecticut for President this November. Even if that number is only about 1%, which is reasonable based on Connecticut's history, that's still near 20,000 voters. Who knows how much higher that number could go if he was included in the debates and was given more media attention.
For the forseeable future, it looks like the Democratic and Republican parties will dominate the U.S. political debates. Finally, with the Commission on Presidential Debates being run by those two parties and requiring 15% support for a 3rd party or other candidate to be included in the debates, there's little reason to believe that things will change anytime soon.