Of course, they've shown a bit less respect for purchases of items in the domain of the First Amendment. Like the PATRIOT act provisions which allow them to demand that booksellers and libraries tell them who's buying or borrowing any literature of interest to them in total secrecy, without any need to show due cause (and their refusal to disclose to Congress even the number of such subpoenas that are outstanding). They've also perhaps, been less than First Amendment absolutists with their vendetta against a reporter, imprisoned for months for refusing to disclose sources.
They've also shown less than total devotion to the Fourth Amendment, with other provisions of the PATRIOT act, which allow access to email headers without a search warrant (clearly less of a privacy concern than, say, gun ownership), and allow federal judges to issue warrants for wiretaps anywhere in the country, allowing them to shop for compliant judges. The indefinite imprisonment of American citizens like Jose Padilla bespeaks a less than perfect respect for either the Fifth Amendment (denial of liberty without due process) or the Sixth (speedy trial), depending on which aspect of the case annoys you most at the moment. But when it comes to defense of the Second Amendment, this administration yields to no one.
Cynics might say that there's political calculation at work here, but it really just reflects a proper balancing of the harms. Certain books could really be useful to a terrorist, and present a clear and present danger. So the need for the government to be able to monitor the purchases of dangerous literature is manifest. But monitoring purchases of firearms is something else entirely.
Contrariwise, guns provide the ultimate defense against a government which is exceeding the bounds of its otherwise permitted powers. We've got examples to prove it. Randy Weaver, for instance, was served by gung-ho law enforcement with questionable warrants --- but he was heavily armed, so things worked out just fine...