O.K. Let’s see how that’s working out.

New Jersey isn’t overseas, but since Sessions and many other Republicans have hailed it as a shining model of austerity, let’s start there. New Jersey ranked 47th in economic growth last year. When Gov. Chris Christie took office in 2010 and began to impose austerity measures, New Jersey ranked 35th in its unemployment rate; now it ranks 48th.

Senator Sessions, do we really aspire for the same in America as a whole?

Something similar has happened internationally. The International Monetary Fund this month downgraded its estimates for global economic growth, with only one major bright spot in the West. That would be the United States, expected to grow a bit more than 2 percent this year and next.

In contrast, Europe’s economy is expected to shrink this year and have negligible growth next year. The I.M.F. projects that Germany will grow less than 1 percent this year and next, while Britain’s economy is contracting this year.

Karl Rove, that sounds a lot like stagnation to me.

All this is exactly what economic textbooks predicted. Since Keynes, it’s been understood that, in a downturn, governments should go into deficit to stimulate demand; that’s how we got out of the Great Depression. And recent European data and I.M.F. analyses underscore that austerity in the middle of a downturn not only doesn’t help but leads to even higher ratios of debt to economic output.

So, yes, Republicans have a legitimate point about the long-term need to curb deficits and entitlement growth. But, no, it isn’t reasonable for Republicans to advocate austerity in the middle of a downturn. On that, they’re empirically wrong.

If there were still doubt about this, we’ve had a lovely natural experiment in the last few years, as the Republicans in previous years were happy to point out. All industrialized countries experienced similar slowdowns, and the United States under Obama chose a massive stimulus while Germany and Britain chose Republican-endorsed austerity.