Much as we might like to deny it, voters are creatures of habit.

In only 13 of the 51 states (including the District of Columbia) did Bush’s two-party margin in ’04 vary by more than three points, either way, from his 2000 showing. In just four states — Alabama, Tennessee, Hawaii and Rhode Island — was the difference greater than five points. In short, by far the best predictor of a state’s voting behavior in 2004 was its vote in 2000.

In a blowout presidential race, many states will be in play. But the closer the contest, the more likely the 2008 presidential playing field is to resemble that of 2000 and 2004. Which means a handful of states could again be decisive.

While Ohio is the additional big electoral-vote state Democrats are most likely to win, Wisconsin is the one we are in greatest danger of losing. Other states are vital and bear watching for ’08, but these two are of particular import in ’06 as well.

We’ve all said it a million times. If John Kerry had just won Ohio, he would be president. But if he had won Ohio while losing Wisconsin, the Buckeye State win would have been for naught. Kerry would have garnered 262 electoral votes, eight short of the magic number.

As I have discussed previously, Ohio is on the cusp of major political change. Chafing under one-party Republican rule for more than a decade, it has been badly damaged by Bush’s economic policies and is the only state in the Union governed by a convicted criminal.

Republican Bob Taft is far and away the most unpopular governor in the country. Today, George Bush is as unpopular in Ohio as he is in New Jersey. And Ohio was one of just 10 states where John Kerry improved on Al Gore’s vote share.

Wisconsin is another state where Democrats showed improvement over 2000: Al Gore won it by some 5,000, votes while Kerry more than doubled that margin to a still-razor-thin 11,000 votes. It doesn’t get much closer than that — literally. In percentage terms, Wisconsin was the closest state in the country. Less than four-tenths of a point separated the winner from the loser.

Both senators are Democrats, as is the governor, though Jim Doyle is the first Democrat to occupy that chair in 16 years. And President Bush is only slightly more highly regarded in the Badger State than he is in Ohio.

But Republicans have demonstrated the ability to win in Wisconsin. The GOP has won five of the past 12 presidential contests. The U.S. House delegation is evenly divided, with four members from each party.

The challenge confronting Democrats is evident from the composition of the state Legislature, where 60 percent of members are Republicans — 19 of 33 state senators and 60 of 99 assembly members.

Targeting has somehow become a dirty word in some Democratic circles. Our egalitarianism resists giving more attention to some states and less to others. But in a close presidential contest, targeting can make all the difference. A change of 59,000 votes in Ohio would have made John Kerry president, even while he lost the national popular vote by 3 million. That is the potential power of focus.

There is no doubt that Governor Doyle’s work for Kerry in ’04 made the difference in Wisconsin. A Democratic governor in Ohio could have meant a Kerry victory there. So while these two ’06 gubernatorial races are critical for those states, they may well have vital national implications in ’08 as well. Targeting these states now will likely pay dividends later.

Mellman is president of The Mellman Group and has worked for Democratic candidates and causes since 1982, including Sen. John Kerry (D-Mass.) in 2004.