If we elected the president by popular vote, we would have heard some different spin going into the debates. With the presidential election looking closer in the national polls than it does in the swing states, the pressure on Mitt Romney from his party and the pundits alike would have been rather less demanding.

In one sense, this is surprising. Our antiquated Electoral College actually gives Republicans an advantage. By guaranteeing every state three electors regardless of population, the system offers outsized influence to smaller, mostly Republican rural states.

In 2000, George W. Bush lost the popular vote to Al Gore. Bush became president not only because the Supreme Court awarded him Florida but also because sparsely populated Western states, from the Dakotas through the Rockies and up to Alaska, boosted his Electoral College total.

In 2012, the system is working in President Obama's favor. If all the pundit talk during the Reagan years was of an "Electoral College lock" for the GOP, the lock has rusted into uselessness since Bill Clinton first picked it in 1992.

Instead, we have what National Journal political writer Ron Brownstein has aptly dubbed the "blue wall" because Democrats now have more states reliably in their corner than the Republicans do. Since 1992, Democrats have never received fewer than 251 electoral votes. In the same period, Republicans averaged just under 167 electoral votes in the three elections they lost. Obama starts with a bigger electoral vote base and thus has more paths to victory than Romney.

There are ample grounds for wariness of sweeping structural explanations in politics. A case can be made that Obama is doing well in the swing states for reasons having more to do with the campaign than with any wall. The president and his allied super PAC have simply been more focused and disciplined than the comparable Romney efforts. Bill Burton, one of the maestros behind Priorities USA Action, the main pro-Obama group, argues that various entities advertising on Romney's behalf have put forth a cacophony of themes and messages that have yet to cohere into a strong, persuasive argument.

Yet broader trends in American politics are making the blue wall thicker. As John Judis and Ruy Teixeira argued in their prescient 2002 book, The Emerging Democratic Majority, Republicans were becoming increasingly a party of older, white Americans at the very moment when the country was becoming much more diverse. Romney's hard line on immigration, which has left him with an anemic share of the Latino vote, has deepened his predicament. It's no wonder he tried to soften his stance on the DREAM Act in an interview on Monday with The Denver Post.

Faced with their weakness among African-Americans and Latinos, whose share of the vote is steadily growing, Republicans need to win something on the order of 60 percent of all white votes to get to a majority.

And this is difficult because significant groups of white voters, notably the overlapping groups of younger voters and professional and technical workers, have been driven away from the GOP in part by its social conservatism. This problem is aggravated by the Democrats' strength, especially pronounced this year, among women.

All these factors play back into the Electoral College. The power of the Latino vote took states that had been reasonably friendly to the Republicans at the presidential level -- Nevada and Colorado, for example -- and made them swing states. Southern states such as Virginia, North Carolina and Florida are no longer Republican-leaning (or GOP bastions) because a combination of African-Americans, Latinos and new migrants in the white professional class has transformed their demography.

In the meantime, the very same factors have made states that were once competitive -- including the electoral vote troves of California and Illinois -- and moved them firmly into the Democrats' presidential camp.

Nearly four decades ago, Lawrence O'Brien, the legendary Democratic operative, wrote a memoir whose title, No Final Victories, embodies one of the best aspects of democracy. In free nations, political triumphs are provisional and those who lose today have a chance of prevailing tomorrow. That's why there is no electoral wall so durable that it can't be demolished eventually. Someday, necessity will force Republicans to come to terms with their problems among Latinos, African-Americans, younger professionals, and women.

But for now, Mitt Romney's trouble in reaching outside the GOP's comfort zone is making his Electoral College problem -- and his task in the debates -- even more daunting.

(c) 2012, Washington Post Writers Group