Sullivan takes a stab at distinguishing among political movements. The good ones make moral appeals, sometimes with religious overtones, in order to make America live up to its constitutional ideals; the bad ones offend the Constitution's values. It is a meaningless taxonomy, since whether he thinks a movement falls on the right side of the Constitution's ideals depends on whether he approves it or not. For example: Is a movement to amend the Constitution to allow states to protect unborn human beings an attempt to live up to America's ideals of equality, or a dangerous theocratic imposition? No doubt Sullivan's answer to that question with vary with the fortnight, but in no case will a simple appeal to "constitutional ideals" do any analytical work in reaching that answer.
I think Ponnoru is right but I think the exact charge can be levelled against his own positions. His views are "conservative" because he, or in a larger sense, the Republican Party holds them. There is no analytical work of applying conservative philosophy to an issue to decide what the "conservative" position is.
Consider stem cell research. Under no rubrik, other than an absolute antipathy to government funding of scientific research (which has never been forwarded as an argument), can the Republcian position be seen as conservative. Republican opposition is completely tied to its political links to the Religious Right, which sees stem cell research as somehow encouraging abortions.
Or the Terri Schiavo affair. If anything, application of conservative principles would lead to a condemnation of Republican actions in that regard, as the federal government not only stepped into a local matter, it did so by disrespecting the local courts.
Or the Iraq War. The idea of preventive or preemptive wars appears to run utterly counter to conservative principles. Indeed. I feel confident that every single Republican who stood in support of the Iraq War would have opposed it if it had been a war proposed by a Democratic Administration. "Conservatism" the philosophy informs nothing done by the Republican Party or supported by Republican pundits like Ponnoru.
There is no conservatism. FDR killed it.