Read the article. The Republicans are just as much a Big Government party as the Democrats. Maybe more so. It is not "the predominant conservative party in America" because it is no longer conservative in any way.
The premise of teh two-party system is that the two parties provide meaningful alternatives. When that premise is violated, then the two-party system is not doing the job it is supposed to do and it is time to seek alternatives.
Yet under Republican governance, the size, cost, and iintrusiveness of government grows even faster than under Democrats! That is no alternative.
What ever happened to "a choice, not an echo"?