Here is my thinking. We do not know what Mitt Romney believes in, what he stands for. Is he a “severe conservative”, or is he a Massachusetts moderate, or is he a more centrist Republican?
The Tea Party extremists have hijacked today’s Republican Party. Congress cannot achieve anything if it is not the Tea Party’s way.
Now, imagine that Mitt Romney becomes President of the United States. According to his behavior so far, he would want to satisfy the Republican Party. Why? Because if he did not work with them, the Republicans might not endorse him for a second term. Working with the Tea Party means conservative Supreme Court judges, cuts in social programs, no new revenues, more tax breaks for the rich, no more regulations for banks.
Now, imagine that Barack Obama is elected to a second term. The Republicans, in order to be relevant and have a chance at getting to the White House, would be forced to change their behavior. They would have to get more to the center, attract more minorities, represent different layers of American society. They would move more to the center, become more moderate.
And this would be good for the Republican Party and probably very good for the whole country. Two heads are better than one; two functional parties are better than one.