They are going to lose a lot more voters than they could hope to gain.
That's my thinking as well. I'm not going to be able to go to the polls and vote if "traditional values" are thrown over board for political expediency.
I have two children in college and when they bring friends by we will discuss issues like homosexual marriage. Almost all of them start out in favor of it. I will ask them what is the basis of the moral code that society should be governed by. In some cases they revise their thinking.
It seems to me that in a culture that wants "bumper sticker answers" to problems we are fighting at a disadvantage. Conservative principals are based in a much more complex rigor of thought.