In between worrying about what to do about the chaos in the Middle East, the political world in the United States is mostly occupied this week with the debate over the federal budget, and in particular, what to do about its frighteningly large levels of debt.

Introducing the topic last night on The 7.30 Report, Michael Brissenden told us that “At every level of government in America today, there is one crushing central issue: money – or rather, the lack of it.”

Certainly that’s what you’d think if you were just looking at the political rhetoric. But if you dig a little deeper, there are several reasons for thinking that the debate is not primarily about money at all.

For a start, if the deficit was the big worry, it would be mysterious why Republicans were thought the party most likely to deal with it.

After all, the only president to seriously get the deficit under control in the past 30 years was Bill Clinton, a Democrat. Under Republicans Ronald Reagan and George Bush jnr, the US government ran huge deficits without apparently worrying the party’s voters much at all.

Republican fiscal policy has basically amounted to cutting taxes and letting the expenditure side look after itself — and while the tax cuts may or may not have helped the economy, they certainly didn’t help the deficit.

Despite the hardline debt and deficit rhetoric of the Tea Party activists, that pattern continues. The GOP’s alternative budget proposes $61 billion worth of expenditure cuts, but much of that depends on cutting unspecified “waste” and other dubious measures. It’s not clear that the savings can actually be delivered when it comes to legislating — and even if they can, $61 billion won’t make much impression on a multitrillion dollar debt.

Some on the left have pointed to the inconsistency and concluded that the Tea Partiers are driven not by concern about the debt, but by opposition to government spending in general — that their objective is not to reform government but to bankrupt it.

But I don’t think that’s quite right either. While Republicans are fond of anti-government rhetoric, their hostility to actual government spending is limited to a small number of programs that collectively represent only a tiny fraction of the federal budget: foreign aid, unemployment benefits, public transport, subsidies for alternative energy and one or two others.

This, of course, ignores all the really big-spending items: defence, military pensions and benefits, social security, Medicare, Medicaid and interest on government debt. Without bringing some of these areas under control, the debt mountain will continue to grow.

The New Republic’s Jon Chait recently drew attention to an interesting Pew survey on attitudes to government spending. As he points out, even among evangelical Christians — a key support group for the far right — spending increases are more popular than cuts in almost all areas; only with foreign aid would a majority of evangelicals like to reduce spending.

When it comes to defence, the budget’s largest black hole, evangelicals were actually less likely to support cuts than the general population.

Ditto for agriculture, another favoured Republican constituency.

So while the Republicans’ motive is pretty obviously ideological, it’s not an anti-government ideology, it’s just anti some particular groups and causes that fall foul of the right’s worldview. Meanwhile, the GOP’s allies in the media are doing their best to convince the public that these things represent a far greater share of the budget than is really the case.

Don’t get me wrong, I think that big cuts in government spending are possible and desirable. They’re also not difficult in principle; they just require political courage. The defence budget could be gutted, Medicare and social security could be means-tested, farm subsidies and other middle-class welfare programs could be eliminated.

But only a handful of Republicans show any interest in things such as that.

The interests of most of them are quite different: it’s all about targeting their political enemies and attacking not government per se, but a government that they don’t control.

That’s become most obvious from the standoff in Wisconsin, where Republican governor Scott Walker is trying to cripple public sector unions under cover of a budget rescue package. His opponents have said they’re willing to concede cuts to pension benefits, but what Walker is pushing for is getting rid of collective bargaining rights. It’s no longer about money, if indeed it ever was.

The lesson of Bill Clinton’s 1992 campaign was supposed to be “It’s the economy, stupid.” But to understand the budget wars of today, it’s necessary to realise that the leading actors care about the politics much more than the economics.