Writers about American conservatism have often observed that the word itself has meant different things at different times and that there is no consistency in conservatives' beliefs about what should be conserved. This truth need not be surprising; conservatives have generally taken an antitheoretical approach to their world. American conservatism, moreover, has often been reactive, responding to perceived political and intellectual challenges. As the challenges and threats changed, so did the nature of the conservative response. Beliefs that once seemed radical later came to seem conservative.
Nevertheless, Allitt's thesis is that there has been a "conservative" side in every contentious period in American history. The problem is whether the side he identifies as "conservative" is the one today's self-identified "conservatives" endorse. For instance, in the early national period he identifies the Federalists as the "conservative" party, while most self-styled conservatives of the present day probably identify with the Jeffersonian side because of its advocacy of limited government and states' rights. A minority of conservatives of more populist leanings might side with the Federalists because they agree with Alexander Hamilton on the need for protectionist trade policies, but many more, from what I can tell, have endorsed the principle of free trade as part of the broader concept of free enterprise -- an idea which itself was problematic for many conservatives of the 19th century. Also, it's quite possible for a 21st century conservative to claim that Federalists and Jeffersonians alike would be conservatives by the present standard, just as it's possible to argue that both sides from the 18th century would agree that all sides of the present system are irredeemably corrupt, or that the people as a whole are irredeemably depraved.
The meaning of the word "conservative," in a political context, has changed since the days of the Founding. Allitt adheres to the philosophic sense of the term, which opposes conservatism to "radicalism." Federalists were conservatives, by this standard, because they believed (or simply charged) that opponents from Jefferson to Paine wanted to undertake fundamental root-and-branch reform of the entire social order. That anti-radical aspect of conservatism persists, but in political terms, as we well know, the word is now opposed to "liberalism," which is not the same as "radicalism" (despite what some say) but really signifies a form of permissiveness in which people are allowed to have things they allegedly don't deserve and do things they allegedly oughtn't. It's all to obvious to any sentient observer that "liberals" are often just as opposed to radical reform as conservatives, and are actually more inclined to accuse conservatives of radicalism than to indulge in it themselves.
Allitt thinks there is at least one connecting thread that unites American conservatives across the ages. That would be anti-egalitarianism, an opposition to the idea that equality should extend beyond the "before the law" concept to minimize class differences and restrain excesses of wealth. In the earliest times, Federalists (and some Jeffersonians) resisted extending the right to vote to people without landed property, not to mention women or racial minorities. Federalists in particular supposedly resented the idea of having to electioneer and pander to plebeians, expecting to be recognized for their superiority without having to advertise themselves. Today's conservatives still resist the idea of social equality, since it violates their ideal of just desserts, but they've definitely abandoned the snobbishness of their supposed Federalist forebears, as the anti-intellectualism of Republicans from Joe McCarthy to George W. Bush will attest.
It may be true that in every meaningful political conflict in U.S. history there's been a "conservative" side, but how useful is that information, really, especially when Allitt concedes that there's never been a monolithic, consistent conservative movement carrying the same package of ideas from the Founding to the present? I suspect that Allitt takes the "conservative" label too seriously just because so many conservatives (and liberals) do. It may be harsh to say this of a college professor, but I also suspect that the "Conservatives" label makes his treatise easier to sell. He'd definitely have nothing to sell, maybe even nothing to say, without it. I'm going to press on with the book because it might have something interesting to say about reactionary movements through history, but if anyone picks it up thinking that it'll explain today's conservatives in a historical context, I think they're in for disappointment.