“WE WORSHIP an awesome God in the blue states,” declared Barack Obama in the speech that made him a star, “and we don't like federal agents poking around in our libraries in the red states.” Six years after his address to his party's national convention in 2004, the idea of Mr Obama as a post-partisan figure, an effortless uniter of Democrats and Republicans, looks droll.

But his failure to transcend party politics does not mean it was not canny to try. In America, Europe and elsewhere, the era of tight affiliation to political parties is over. Successful politicians surmount party allegiances, rather than entrench them. In America, the “50-50” nation is more like a 30-30-30 nation; last month, a Pew survey found that “independents” at 37% outnumbered either Democrats or Republicans. Such inbetweeners tend to find partisanship on the airwaves and in Congress repellent, strengthening their convictions further.

As old allegiances fade, third parties are doing better. In Germany, a recent poll puts the Greens, formerly a fringe party, ahead of the once impregnable Social Democrats. In Britain's 1951 general election, 97% of all voters chose Labour or the Conservatives. In last May's election, just 65% did. Party membership is declining too—by 40% in 13 European democracies between the late 1970s and late 1990s, according to one study. In Britain the three big parties combined have under 500,000 members; in the 1950s, with a smaller population, their total was over 4m. And the members that remain are less active.

Explanations abound. In many industrial democracies, working-class voters chose left-wing parties out of self-interest. Other voters, fearing the power of organised labour, voted the other way. But when most people count themselves as middle-class, such tribal ties wane. In countries where the ideological gap between parties has narrowed, their brands may no longer be useful labels for busy or ignorant voters. Accustomed to choice as consumers, voters increasingly pick policies rather than signing up to comprehensive world views. Single-issue groups have thrived. Britain's National Trust, a heritage organisation, raised its membership from 250,000 in 1971 to 3.7m now.

Political scientists disagree over the causes of the parties' decline. But a more pressing question is its effects. The decline of partisanship could signal a less tribal, more educated electorate. But research on 36 countries by Professor Paul Whiteley of the University of Essex shows a strong correlation between political partisanship and good public administration. A rise of ten percentage points in partisanship goes along with an increase of one notch in the World Bank's good-governance table (which assesses countries on a five-point index). A strong party base may help politicians to push through unpopular but necessary reforms. A weak one means that followers flee when the going gets tough.

Consumer choice may mean dodging responsibility. California's referendums allow voters to engage with politics issue by issue. The state's dysfunctional finances and politics are a poor advertisement for that. Less partisanship can also mean more political volatility as big old parties find it harder to win outright. The Westminster model of parliamentary democracy and majoritarian voting should produce strong single-party rule. But the most recent elections in the five main countries that use it (Australia, Britain, Canada, India and New Zealand) have produced hung parliaments. Four have coalition governments.

The parties' efforts to reverse this have had little success. As Conservative leader a decade ago (he is now foreign secretary), William Hague proclaimed a target of a million-strong membership. It is now less than 200,000. A better solution may be to give members real power within the party. Maurice Duverger, a French academic, distinguished in 1951 between “cadre” parties, where power is held at the very top, and “mass” parties, where the grassroots decide policy and elect bigwigs. Most political parties in the West offer influence to outsiders who donate money, not to their members who donate time.

The decline of partisanship is prompting some innovations. Some Americans favour the idea of “top two” primary elections in which any registered voter can take part, and choose two candidates, regardless of party, to contest an election. The victors could be two Democrats or two Republicans. The system is already in effect in Washington state and was recently approved in California. It could help cross-party and moderate candidates. But it faces a stiff legal challenge.

Other efforts seek to turn independent politicians—often seen as cranks and amateurs—into effective candidates. In Britain, outfits such as Independent Network and the Jury Team offer training and support to independents. Brian Ahearne, director of the Independent Network, says that Britain's most recent general election saw the biggest number of independents standing for election since 1885, when records began, and almost twice as many as stood in 2005. They received over 144,000 votes, against a mere 10,000 in 1987.

Politicians like to have it both ways. “Vote for my Daddy,” quavers Ben Lange's toddler daughter, in a spot for his candidacy in an Iowan congressional race. Grouped with his family on a sunny mid-western hillside, Mr Lange gives a wide berth to party politics. “This isn't about Republican/Democrat,” is his cutesy patter. But another campaign video on his website is bombastic and combative, showing grainy footage of political foes, with a sinister musical soundtrack. The old system may be broken. But it is not dead yet.