By Bob Benenson, CQ Staff

The emergence of Barack Obama as the putative front-runner for the Democratic presidential nomination has of late spurred some early discussion about whether he has an opportunity to break the “blue state, red state” dichotomy that delivered very close electoral-vote victories to Republican George W. Bush in the past two elections.

Obama’s campaign — seeking to establish a solid edge for their candidate over New York Sen. Hillary Rodham Clinton on the important subjective measure of “electability” — argues that the Illinois senator can compete in states that typically vote Republican for president and many other offices (and are colored “red,” as opposed to Democratic “blue,” on political maps).

As evidence, they present exit poll results that show Obama drawing unusually strong support from independents and Republicans in those primaries so far in which non-Democratic registrants have been allowed to vote.

Obama fans also point out that he has strongly outrun Clinton — and drawn unusually high turnouts — across states such as Kansas, North Dakota and Idaho, and in rural areas of other states, which Democrats usually forsake because of their strong historic Republican allegiances in presidential politics.

These claims have been countered by some doubts expressed in the media analyst community, and outright scoffing by Republicans. GOP activists contend that Obama’s Senate record and policy prescriptions are too liberal to withstand the thorough going-over they will get from the GOP’s nominee — almost certainly Arizona Sen. John McCain — and from the national Republican Party and allied outside groups that will spend tens of millions of dollars trying to paint Obama into the corner on the left if he is the nominee.

Yet it will be crucial for Obama to compete on traditionally Republican turf if he hopes to build any sort of an electoral comfort zone during the fall campaign. And the same is true for Clinton, who must find a way to improve her appeal among Republicans and especially among Republican-leaning independents should she stage a comeback to win the Democratic nomination — that is, if she wants to have any hope of avoiding a cliffhanger election like the ones lost to Bush by Al Gore in 2000 and John Kerry in 2004.

That is because the “blue state, red state” divide forces the Democrats to campaign on a very sharp knife’s edge. The states that they have typically dominated in presidential politics since the early 1990s — in the Northeast, through much of the Great Lakes region and along the Pacific Coast — are enough to render the Democrats competitive in any presidential election, but leave them short of the 270 electoral votes that constitute a winning majority.

As they strategized about how to get over the top, Democrats in both of the Bush elections fell into a trap of marshalling their forces for a push in one big state: Florida in 2000 and Ohio in 2004. While Democrats can argue from here to eternity about the legitimacy of the controversial vote count in Florida eight years ago, history records that Bush was awarded that state’s electoral votes, as well as Ohio’s when he won re-election in 2004.

In both years, the Democrats made initial moves at competing for several other traditional or potential swing states, but drew back, with troublesome results for the party.

It wasn’t just that the Democrats’ failure to compete seriously in places such as Tennessee, Missouri and West Virginia in 2000, and Missouri, Nevada and Virginia in 2004, cost the Democrats those states’ electoral votes, as Bush likely would have been able to maintain an edge in all of those states.

But the fact that the GOP did not have to play serious goal-line defense in those states enabled them to shift financial and human resources not only to crucial battleground states such as Florida and Ohio but also to politically competitive “blue” states that the Democrats counted on winning with relative ease.

This in turn forced the Democrats to divert their own resources to fend off the Republicans’ rear guard actions in places such as the Upper Midwest. The Democrats succeeded, but in some cases just barely.

For example, Democrats now hold an eight presidential-election winning streak in Minnesota, but carried the state by only 2 percentage points in 2000 and by less than 4 points in 2004. Wisconsin, where the Democrats now have a five-election winning streak, went for Gore over Bush by just two-tenths of 1 percentage point and for Kerry by four-tenths of a point.

While it is not at all clear at this early stage of the presidential race that the Democrats can break out of this strategic box, it has to be the strongly stated goal of either Obama or Clinton to reverse this dynamic and take the fight from states that are marginally Democratic to swing states narrowly won by Bush in 2004 and others that can be argued to be, within reason, just marginally Republican.

Some Democratic targets are obvious. There is Iowa and New Mexico, both of which went to Bush by margins of less than 1 percentage point in 2004. There is Nevada, site of a 3-point Bush win last time. Bush won by less than a 5-point margin in Colorado, a state where the Democrats have gained serious ground throughout this decade. And Missouri, though it went to Bush by a fairly solid 7-point edge, still has enough of its traditional reputation as a bellwether state intact to tempt a Democratic foray this year.

Many red states — Utah, Idaho, Wyoming and much of the South are obvious examples — are unassailable Republican strongholds. But the Democratic National Committee’s commitment under Chairman Howard Dean’s “50 State Strategy” to rebuild state party organizations where they had gone vestigial may at least enable the party to make its presence known in some Republican states through November.

The Democrats even have a bit of a road map in developing this strategy, from its success in the 2006 midterm House elections that boosted their party into a majority.

In previous elections after the big Republican upsurge of 1994, Democratic House campaign strategists also allowed themselves to get boxed in. They focused their limited resources on a very small subset of Republican seats in districts known to be “competitive.” The problem with this strategy is that the Republicans, who typically had greater resources, were able to draw the line in these districts and easily parry the Democrats’ thrusts.

In 2006, the Democrats — under the strategic leadership of Illinois Rep. Rahm Emanuel , then chairman of the Democratic Congressional Campaign Committee — broadened the “playing field” by recruiting stronger-than-usual challengers in a number of districts that the party had essentially ceded to the Republicans over the years. In the meantime, they also competed all out in the traditionally competitive districts.

The outcome had a very interesting twist. Several of the seemingly most vulnerable Republicans, representing swing districts, were able to survive with the help of the party’s House campaign unit, the National Republican Congressional Committee, which poured vast financial resources into those campaigns. But the Democrats were able to light too many brush fires in districts that had long been Republican strongholds, especially given the strong turn in public opinion against the GOP in 2006.

The simplest rule in politics is that you can’t win where you don’t play.