The Republican party is not stupid, they know America is growing ever more liberal. They can see the polls showing that even a majority of Republicans support gay rights and increased taxes on the wealthy and legislative efforts to increase access to contraception.
That last reference is the most telling, for it points out that:
Only 8 percent of Republicans and Independents think the government should support abstinence-only programs. A strong majority of Independents (76%) and Republicans (62%) believe the government should support comprehensive sex education programs that include information about abstinence, as well as information about contraception and sexually transmitted diseases.
Self-identified “strong” Republicans prefer comprehensive sex education over abstinence-only programs by a 56 percent to 14 percent margin.
Two-thirds (67%) of Republicans and Independents prefer a Senate candidate who favors teaching comprehensive sex education in public schools over a candidate who favors teaching abstinence-only.
Now compare the results of this poll to the legislation that Republicans are passing across the nation; it doesn't match up, does it? But why do they do it? Look at the first phrase in that last quote: "Only 8 percent". It's that eight percent, and the Republican minority on the other issues, who are most likely to vote in the primaries and in the general election. They represent the furthest right of the right. It's that minority of the Republican party who are forcing their politicians and their presidential candidates to take positions that the majority of Republicans simply do not want but, since they are Republicans, will vote for anyway.
America and the world are growing ever more liberal, that much is obvious. And the more liberal the world grows, the more threatened those on the right will feel. That is the root cause of their ever-further-to-the-right claims and political positions. I believe this trend will not abate until the Republican party suffers a true landslide defeat. It might happen this time, but I don't think so. The time is not yet. It is coming, but not yet.