1) What is a Presidential Signing Statement?
2) Re your contention that Bush lost popularity because of the Patriot Act, I'm sceptical because it affected so few people.
http://en.wikipedia.org/wiki/Presidential_signing_statement
Presidential Bush created a constitutional controversy by adding signing statements to bills that in effect said, “This is how I interpret the bill and intend to enforce it (or not)”, which was sometimes at variance from how congress intended the bill to be enforced. It will eventually have to be decided by the Supreme Court.
Actually, the Patriot Act affects every American. Not just heightened security at airports and bus terminals, but the authorization of warrant-less surveillance, wiretapping and databasing of Americans has reached ridiculous heights.
Before, if you made four domestic long distance phone calls a month, one of them on average would be examined by the NSA, with text analysis, and solely for national security reasons. The Patriot Act changed that so that any phone calls you make can be monitored without cause, and evidence gathered for potential prosecution for any sort of crimes.
They have really overdone it, and their needs to be a severe curtailment of domestic intelligence operations by organizations like the CIA, the US Army, and a dozen other agencies whose functions have no bearing on domestic crime.