A political party cannot be all things to all people. It must represent certain fundamental beliefs which must not be compromised to political expediency, or simply to swell its numbers.
http://www.mofopolitics.com/2008/11/05/ronald-reagan-1975-cpac-speech/
Reaching across and compromising with your enemy apparently is the preferred method. Maybe to the GOP-e, those sitting across the aisle, don’t hold such different views.
To find votes, they’re going to sell it that Mitt and McConnell and Boehner will be ready, willing and able to “work for the American people” by working with the opposition.