It’s a familiar, all-purpose excuse that liberals often use when things go wrong for them: Republicans, they insist, have sneakily moved the boundaries of public debate so that it no longer centers on the middle, but somewhere on the right. This is sometimes more self-serving than accurate. But they have an increasingly good case when it comes to the debt-limit debate.

A new Reuters/Ipsos poll found that just 19 percent of Americans favor a debt-limit deal that only cuts spending, the GOP position. That’s not so far from the 12 percent who want only tax increases in a debt-limit bargain. That 12 percent is left even of the Congressional Progressive Caucus’s all-but-forgotten debt-cutting proposal , which, of all the major plans lawmakers have put on the table, is actually the most fiscally responsible .

This doesn’t argue that liberals should be just as intransigent about their approach as the Republicans have been about theirs. The poll — and, conveniently enough, good policy — argues for the middle path that President Obama now favors. Reuters found that 56 percent of Americans want to see a plan balanced between spending cuts and tax increases. Tax increases — a term that shouldn’t even apply to the tax reforms that Obama proposed to raise federal revenue, which should be much less controversial.

Unfortunately, that middle path died over the weekend, along with the hopes of those of us who wanted to see a big bargain on debt that dealt realistically with America’s long-term fiscal imbalance, a bargain whose sheer size would have required both spending cuts and increases in federal revenue to produce the many trillions in budgetary sanity needed. Instead, the debate in Washington is now about what version of the GOP’s 19 percent plan will ultimately pass.