There's just no getting around the fact that there is a large conservative marketplace, and that there's more money that can be squeezed out of that market when Democrats take office. I don't know that any conservative operatives actively follow the obvious incentive and consciously try to make their own side lose elections, but the incentive most certainly exists, and may well affect behavior in some cases.Fox News functioned, in many ways, as a White House mouthpiece during Bush two terms, and it did fine in that mode, but of course the White House already has its own communications structure. Conversely, Fox News was born under Clinton's presidency and has thrived under Obama's. I don't know how Glen Beck voted in 2008, but if he'd known how good Obama's presidency would be for his career, I'd lay odds that he'd have pulled the donkey lever that year.
I once heard a comedian say that every election gives us a choice between a candidate that's good for your country and another that's good for your office. Obviously, given such a choice, people don't always vote their pocketbooks (think Barbra Streisand), but they usually do. And I think it's fair to say that the parts of the Republican coalition that profit by being in the minority are increasing in stature within their party.
Parties are certainly entitled to stay in the minority if they want to, but a lot of electoral outcomes are beyond their control. So what happens if a party takes increasingly irresponsible stances and then becomes the majority party anyway? We may find out later this year.