Conservatism is the belief in established traditions as a hard-won storehouse of wisdom. It should be changed, and only slowly and with great debate.
Liberalism is the belief that society needs large breaks with the past to save itself from itself.
Things like gay marriage, or abortion before it, or minority rights before it, can't come into being until a critical mass of society gets behind it. Only then can a handful of vanguard judges try to declare a change, legislating from the bench, or would Congress even dream of passing different laws.
At that point, people play mind games with themselves that, golly, everyone opposed is evil incarnate. Yet only a few years earlier, any politician saying that would get their hat handed to them at the next election.
What one takes from this is to just keep pushing on those ideas if you want to change them. "Liberalism" as harbinger of change only precedes conservatism by a few years or a decade. Many states were liberalizing abortion laws by conscious decision and legislation when some judges decided critical mass had been achieved and they changed things for all.
As far as spending goes, Bush, Jr., increased spending a lot, especially near the end of his term. This is a liberal position, and he was called on it at the time.
I find it interesting that you call conservatism "bankrupt" insofar as the politicians deviate from it into liberalism.
