Anti-war Congressman John Murtha of Pennsylvania is prominent among some Democrats in his use of the "I" word -- impeachment -- about President George W. Bush and Vice President Dick Cheney. Murtha made his comments on CBS's "Face the Nation" and elsewhere.

Few serious observers think things will ever get to actual impeachment. And yet the American public seems more open to the concept than many imagine, according to a new national poll. The implications of this public sentiment could be huge for the 2008 presidential elections.

Our InsiderAdvantage/Majority Opinion poll asked this:

"Would you favor or oppose the impeachment by Congress of President George W. Bush and Vice President Dick Cheney?"

Favor: 39 percent.

Oppose: 55 percent.

Undecided/Don't Know: 6 percent.

The survey of 621 registered voters has been weighted for age, race, gender and political affiliation. The poll has a margin of error of plus or minus 4 percent.

About four out of 10 Americans favor impeaching the president and vice president. But the biggest news from this survey is not the overall results, but the opinions of independent voters, who usually decide presidential elections.

Forty-two percent of independents want Bush and Cheney impeached. These aren't just voters who disapprove of the White House. Instead, they're for initiating a process that could remove them from office.

To help put these startling numbers into perspective, I turned to the man most identified with the impeachment of Bill Clinton in the 1990s, former Congressman Bob Barr.

Recall that Barr initiated the Clinton impeachment process by filing what's called an "Inquiry of Impeachment." That's a resolution that precedes an actual "Bill of Impeachment." In the case of Clinton, it was filed long before anybody had heard of Monica Lewinsky.

Analyzing the InsiderAdvantage polling numbers, Barr said, "This indicates the surprising depth of dissatisfaction with Bush. Continued...