Republicans come in several varieties. Conservatives do not.
Conservatism by its definition is small government. Nanny state Republicans and Country Club Republicans and other Big Government Republicans can’t be Conservatives. Baby Bush fancied himself a Conservative but in the end, he proved not to be one with the TSA, Homeland Security, big wars, Medicare D and the bailouts.
We haven’t had a Conservative president since Reagan.
Yes, and he called it Compassionate Conservatism. Ugh.
No doubt that's your definition of conservatism, and many self-described conservatives would agree. But lots of folks, like McCain in the example I referred to, have different definitions. Here's a good definition as it relates to politicians in the 21st century:
Conservative, n. A statesman who is enamored of existing evils, as distinguished from the Liberal, who wishes to replace them with others. [Ambrose Bierce, "Devil's Dictionary," 1911]
WRT to Bush II, he supposed it necessary to create "compassionate conservatism" to save conservatism just like he had to "abandon free market principles to save the free market." Of course, he didn't do it all by himself; he had help from the likes of towering conservative intellects like Rove, Frum, Gerson, Dreher and Brooks. And before that, Bush I made short work of Buchanan's paleoconservatism with his own "kinder, gentler" version of conservatism.