An InsiderAdvantage/Majority Opinion survey of 1044 registered voters nationwide shows public opinion evenly split over the opinion provided by General David Petraeus in his report this week to Congress on our progress in Iraq. That's the good news for President Bush, given the many reports and commentaries that suggest the general had a sketchy case.

Now the bad news for Bush and proponents of a 30,000-troop reduction by next summer: By a 58 percent to 34 percent margin, Americans say the reduction is not enough. A majority wants more troops than that home by then.

Here's the key: By a 43 percent to 36 percent margin, poll respondents said they'd be less likely to vote for the Republican nominee for president if a substantial number of troops "have not been withdrawn from Iraq by Election Day." (The other 21 percent were undecided.)

The plot gets even thicker when the poll is broken down by party affiliation. Nearly 20 percent of those identifying themselves as Republicans said they'd be less likely to vote for their own party's nominee if big troop reductions don't happen.

Among those who consider themselves independent voters -- the ones who put recent Republican presidential candidates over the top -- 12 percent said they'd be less likely to vote for the GOP ticket without drastic troop reductions.

What does this all mean? First, it tells us that many Americans recognize that there has been genuine progress in bringing some degree of calm to Iraq. Given the endless drumbeat of bad stories and commentary, that is amazing in and of itself. However, the fact that only 49 percent of all Americans agree with the administration's assessment is hardly cause for celebration at the White House.

The fact is, most Americans originally supported the war, later became skeptical and now want our troops back home. It doesn't mean they don't support the troops or the overall cause. Rather, they have grown weary and can no longer distinguish a clear connection between 9/11 and a continued war in Iraq. Clearly there are arguments to support that connection, but if the public cannot make the mental leap needed to do so, then, from a public-opinion basis, the effort is of no value.

And cute tricks, such as having General Petraeus testify one day before the anniversary of 9/11, have little impact on public perception. To many Americans, the election is about Iraq, stupid.

Oddly, my polling tells me that by November of 2008 the issue will be the same that created disaster for the Democrats and Jimmy Carter in 1980 -- the economy. Remember James Carville's stinging slogan for Bill Clinton: "It's the economy, stupid."

James was right, and he used the issue to create a wedge that -- once Ross Perot's third-party candidacy was tossed in -- worked to elect Clinton.

The combination of Iraq and a threat and the economy should be of great concern to those Republicans vying for their party's nomination.

I believe this election is much like the 1980 battle between Carter and Reagan. A bad economy combined with a seemingly unsolvable international crisis -- the Iranian hostage crisis for Carter -- created huge discontent among the public.

The difference this time is that none of the GOP candidates for president are White House incumbents, as Carter was then for the Democrats. So there's no pressing need for the Republicans to resolve the international crisis prior to Election Day, as Carter needed to do.

Put another way, Bush and his general can make their small reductions in troops in Iraq and hurt only one person -- the coming GOP nominee.

Few remember that Jimmy Carter and his staff came close to negotiating freedom for the hostages just before the election. When the effort failed, Carter's pollster, Pat Caddell, had to inform Carter that the election would likely go to Reagan.

To his credit, Carter tried to resolve the Iranian issue. If Bush and the GOP presidential field remain steadfast in this "stay until we win" mindset, they will likely sentence the GOP to the same fate Carter faced. Defeat.