Most people realize that this country is a 2 party system and are very dubious of these 3rd parties that seem full of loons to begin with. They are not even a viable option to the mainstream.
I disagree. I think we've already got the conditions for a third party, and it will be started by Democrats who are tired of the hypocrisy and extremism of their "leadership."
The "third party" will form in the middle: it will start from moderate-to-conservative Democrats, and will draw in the moderate and liberal Republicans.
The conservative Republicans will keep the name; the remaining far-left Democrats will team up with the Greens; and the new party will inhabit the middle (and probably dominate).