A bit of good news for the 265 sitting members of Congress who voted to extend the legislation that the NSA claims as its mandate to collect phone data: the majority of Americans don't care. Pew Research today released a poll suggesting that 56 percent of the country thinks doing just that is just fine.

The firm, which has clearly been paying closer attention to the history of the NSA than many Americans, asked similar questions about the balance between privacy and terror investigations in 2002, 2003, 2006, and 2010. That history provides some insight into how attitudes toward the subject have changed. Or: haven't.

Asked if it was acceptable for the NSA to intrude on privacy in service to terror investigations, people in 2006, 2010, and today all expressed about two-to-one support for doing so.

On the specific question of warrantless wiretapping — the NSA's apparent ability to catalog data about phone calls — the numbers have shifted just as slightly. For civil libertarians, the trend is actually worse. In 2006, 47 percent of Americans opposed the idea. Now, 41 percent do.

Views on the practice differ significantly based on political party. Democrats support such wiretapping by 30 percentage points; Republicans, by only five.

Which is a big change from 2006. At that point, Republicans supported it by a 52 percent margin; Democrats opposed by 24 points. Below, the two graphs at left show percentage of approval by party in each year; at right, the percent of change over the seven years.

Pew must be very curious what would happen under a third-party president.

One last data point for Congress to consider: Privacy is much more important to young people. While every age group prioritizes terror investigations over protecting privacy, those under 30 are far less likely to do so.

Of course, those young people are far less likely to vote.