Liberals think of politics as a means; conservatives as an end. Politics, for liberals, stops at the water's edge; for conservatives, politics never stops. Liberals think of conservatives as potential future allies; conservatives treat liberals as unworthy of recognition. Liberals believe that policies ought to be judged against an independent ideal such as human welfare or the greatest good for the greatest number; conservatives evaluate policies by whether they advance their conservative causes. Liberals instinctively want to dampen passions; conservatives are bent on inflaming them. Liberals think there is a third way between liberalism and conservatism; conservatives believe that anyone who is not a conservative is a liberal. Liberals want to put boundaries on the political by claiming that individuals have certain rights that no government can take away; conservatives argue that in cases of emergency -- conservatives always find cases of emergency -- the reach and capacity of the state cannot be challenged.
Still...conservatives win nearly all of their political battles with liberals because they are the only force in America that is truly political. From the 2000 presidential election to Congressional redistricting in Texas to the methods used to pass Medicare reform, conservatives like Tom DeLay and Karl Rove have indeed triumphed because they have left the impression that nothing will stop them. Liberals cannot do that. There is, for liberals, always something as important, if not more important, than victory, whether it be procedural integrity, historical precedent, or consequences for future generations.
And nothing did stop them, until they ran smack-dab into the American voter at the polls. If they came to power again, then again nothing would stop them except being kicked out of power yet again. The philosophy that the author describes above is ingrained in the modern GOP and the brand of "conservatism" that dominates it. It cannot be undone except perhaps by Republicans spending so much time out of power that their party and governing philosophy are inherently altered.
So, enough of this talk about how the Democrats should treat the Republicans. Republicans can sit on the sidelines and howl about the unfairness of it all but as long as Democrats play the game smarter than the Republicans did, that's all they'll be able to do for the indefinite future. The only fear Democrats should have is one of over-reaching and suffering the consequences of hubris as Republicans did, and that is a minor, minor fear reserved for future consideration compared to other issues they must grapple with. The country must be put back in order first, and the course of a war must be altered. This is no time to discuss the application of the "golden rule" to politics.