Just hours after Hillary Clinton promised to give the nation more Obamanomics if she wins the White House, the Commerce Department reported that the US economy grew at just a 1.2 percent pace in the year’s second quarter, about half the rate most economists had expected.

And even that growth came mainly from consumer spending: Business investment — the kind of thing that means new jobs down the line — is dropping.

Worse, revised data now show a grim trend: The slowdown’s been getting worse ever since it began at the start of 2015. The Obama era is now all but certain to be the first presidency to never see a full year of 3 percent growth.

Mind you, even the best of the Obama economy has rested mainly on just two big things: 1) the Federal Reserve’s unprecedented Quantitative Easing efforts, in which the Fed bought billions in private-sector bonds to goose the financial markets, and 2) the fracking revolution, which gave the US energy sector a huge boost before the global glut drove prices down.

Nobody really expects the Fed to have any more good tricks up its sleeve, and in any case QE did a lot more to help Wall Street than Main Street.

Fracking might boost US growth again when energy markets take their next turn. But Clinton says she’s anti-fracking, too: The Democratic base hates it.

Which leaves her with nothing — zilch, nada — in her agenda that credibly promises to boost the economy: It’s all gazillionaire-dollar tax hikes in the name of “fairness,” plus more free stuff from expanding ObamaCare to debt-free college.

Bill can’t really help: She’s already repudiated all his 1990s policies.

Yes, Donald Trump has himself slammed one of those policies, the NAFTA trade deal — but he’s strongly pro-fracking and promises major tax cuts to get businesses investing in new jobs, as well as serious reform of Obama-era regulations that make it even harder for any company to grow.

If you want the country to escape the slow-growth doldrums, something big needs to change in Washington — and only Trump promises change. Clinton just says she’ll get better results from what Obama’s been doing for the last 7½ years.