WASHINGTON — In case you’ve been out of the country for the past 25 years and were afraid that nothing had stayed the same, here are some current events you may find comforting: Bon Jovi is touring. The Russians are spying on suburbia. And Democrats in Washington are squabbling over the direction of their party.

The latest flare-up of Democratic disunity has to do with how the party should respond to an explosion in government debt. This is a serious policy debate, obviously, and something of a political one, too, since both sides also have in mind November’s midterm elections. But in a more fundamental way, the argument over fiscal policy represents the churning of a cultural fault line that has defined and destabilized Democratic politics pretty much since the onset of the Great Society. And President Barack Obama is only the latest Democratic Party leader to find himself tossed about in the tremors.

A minority of congressional Democrats are already objecting to proposals supported by most of the party for billions more dollars in deficit spending this year on unemployment benefits and state aid as a way of trying to avert a double-dip recession. The bigger argument is how quickly and aggressively Washington should act in the next few years to rein in government debt, which by 2020, the Congressional Budget Office tells us, could reach 90 percent of the gross domestic product.

A lot of Democrats maintain that deficits remain a distant concern at a moment of crisis, especially while interest rates are historically low. A growing faction, however, insists that if Washington doesn’t get serious now about scaling back entitlements and other government spending, then fiscal ruin might be just a decade away.

Obama, as is often his way with internecine disputes, has tried to mollify both camps. After focusing exclusively on spending and job creation during his first year, he has recently pivoted toward addressing the debt, creating a bipartisan panel on deficit reduction and proposing, among other things, a three-year freeze in most discretionary spending.

To understand why these relatively modest proposals are so contentious, you have to put aside for a moment the argument over Keynesian theory and look, instead, at the underlying breach in the party, which concerns the fate of American liberalism itself.

Beginning in the Nixon era and culminating in the 1990s (when Bill Clinton’s New Democrats ascended to power), one faction of the party has always granted that conservatives have a point about the excesses of liberal government. A succession of Democratic leaders, mostly from the South and West, have argued that big federal programs need to be reformed — that we need to move past "the era of big government," as Clinton put it — in order to keep liberalism relevant.

Among more traditional Democratic activists, however, such arguments for modernization have always been viewed as nothing short of a capitulation to conservatives. By this thinking, the idea of liberal government has taken a battering not because it has failed in any significant way, but because expedient Democrats like Clinton have cowered to their critics or sacrificed principle to transient political benefit. When liberal activists hear someone within their own party call for fiscal responsibility, they reflexively assume that the speaker is just looking for ways to slash benefits for the poor, all while claiming to be a "modern" kind of Democrat.

In some ways, given this longstanding cultural divide, Obama should be better situated to sell reform to his party’s skeptical base than any other president in the past 40 years. That’s because all of his immediate predecessors were either Republicans or centrist Democrats, and all of them aroused immediate suspicion from the left whenever they talked about reining in the growth of government spending. Obama, on the other hand, is the first Northern, urban Democrat in the White House since John F. Kennedy — and, of course, the first black president. Progressives have generally been more apt to trust him than they were Clinton or Jimmy Carter.

What’s more, Obama has already succeeded in spending more of the government’s money than any other president in a generation, a record that includes the liberals’ long-sought goal of subsidizing health care for the poor. You might think that would give the president credibility when he argues that making government more responsible does not necessarily mean being less responsive to the poor.

"There’s an opportunity now to have a very serious discussion, if progressives can get out of their crouch, just waiting for the roof to cave in," said Andy Stern, the former president of the Service Employees International Union and now a member of Obama’s debt commission.

In fact, though, Obama’s reserve of trust among his own party’s progressives has been fast eroding. Liberals have been disillusioned over the president’s choice of economic advisers, his escalation of the war in Afghanistan and his willingness to back away from a government-run health care plan. They view the president, increasingly, as a Clintonian modernizer at heart, and they don’t seem at all inclined to hand him a machete and let him have at the federal budget.

"In terms of cutting benefits, in terms of going after the programs that matter to huge amounts of American people, I don’t think you get the support of many of us," Sen. Sherrod Brown, D-Ohio, said in a recent interview.

What this means is that if Obama is serious about changing the nation’s fiscal trajectory, he will not necessarily be able to rely on his own party’s majorities — even if he keeps them in November — to get it done. Instead, the president would probably have to build a genuine coalition of lawmakers from both parties (and not the kind of coalition that features a single Republican vote, secured through all manner of groveling and compromise).

Such bipartisan cooperation, the kind Obama spoke of in his campaign, now seems like a relic from some distant past. Then again, if Bon Jovi and the Cold War can come roaring back, anything is possible.