THE week has not gotten off to a good start for Mitt Romney. His talk of taxes and dependency has put him in hot water, and yesterday his campaign announced that they were pivoting towards specificity on issues such as immigration reform and budget balancing. Mr Romney's gaffe about the 47% may not make much difference in the campaign (a contention my colleague will be taking up in a separate post), but the candidate's new approach to the issues will continually cause him heartburn.

This is because the competing blocs within the Republican Party—pro-immigration businesses versus nativists, tax-cutting zealots versus defense hawks and retirees who want to keep their entitlements—keep Mr Romney from promulgating coherent proposals on issues such as immigration and the budget. And these are just two of the areas where Mr Romney faces such conundrums. He is also trying to appeal to ardent social conservatives who hold minority positions and reach out to swing voters. So, for example, he has avoided taking a position on a proposal that would ban private employers from discriminating against gays and lesbians. Similarly, he has twisted himself into a pretzel over the Lily Ledbetter Fair Pay Act.

This raises an obvious question: why does Barack Obama not suffer from the same paralysing tensions within his coalition? And why have liberal Democrats not forced Mr Obama into a political corner as conservatives have Mr Romney?

Historically it has been the Democrats, not the Republicans, who were viewed as a loose collection of interest groups rather than a cohesive movement. (Hence Will Rogers famous joke: “I am not a member of any organised political party. I am a Democrat.”) If you went to the parties' conventions, it was clear from the delegate demographics that the GOP is still more culturally cohesive than the Democrats. Republicans are basically one group—suburban and rural white Christians who are mostly middle class and wealthy—while Democrats are a disparate bunch.

But ideologically, and in terms of their economic interests, the Democrats are actually more unified. Take a sample of representative Democrats: say, a Puerto Rican janitor in Newark, a gay white fashion designer in Manhattan, a Department of Labor analyst who lives in Maryland, a unionised steelworker in Ohio, an unemployed single mother in Detroit, and a personal-injury lawyer in Seattle. Sure, they have a lot less in common socially than most Republicans do with one another. (That’s why you never hear Democrats screaming, “I want my country back”, or denigrating their opponents as culturally un-American.) But their respective interests are not mutually exclusive with one another. Mr Obama’s embrace of gay marriage did not require him to cut food stamps. Supporting card check neutrality for unions does not interfere with opposing tort reform. In fact, all of these positions can be collectively thrown together under the rubric of fairness and equality. In a campaign based on these themes, Mr Romney makes an especially convenient foil.

The Republican nominee's biography and awkward, patrician bearing don’t only cause him trouble with downscale swing voters. The other reason Mr Obama has more room to manouevre than Mr Romney is because of who he is, and who Mr Romney is. Democrats trust a black constitutional law professor and community organiser from Chicago to have the right values. If he crosses the teachers unions by embracing education reform, or encroaches on civil liberties by carrying out extrajudicial killings of terrorists, Democrats give him the benefit of the doubt, allowing him to also appeal to moderates. Mr Romney, being a formerly-moderate Mormon from Massachusetts gets no such leeway from conservatives. The result is that he is running on a platform of irreconcilable contradictions, while Mr Obama presents more balanced plans, such as reducing the deficit through spending cuts and tax increases. Supposedly the political-science fundamentals of this election favour Mr Romney. But these exogenous circumstances seem to strongly favour Mr Obama.