If you've got more than two parties, it's difficult for one of them to get a majority. A switch of just a few votes can bring down the government.
Our present difficulties stem from the fact that after 70 years of Dem rule, the GOP is now winning some of the races, and the electorate is split 50-50. I don't know how you solve that problem by introducing a third party.
Yeah, the parties tend to look similar because they are both fighting for that 51st percent of the vote. But as soon as the people make up their mind which direction they want to go--to the left or the right--all of this is going to change.
"and the electorate is split 50-50. "
Not exactly. Independents far outnumber either "dems" or "pubbies." The days of one party having a solid majority the way the "democrats" did with the Iwo Jima generation are long gone.