Less than a week after presumptive GOP nominee Mitt Romney tapped Rep. Paul Ryan as his running mate, President Barack Obama used his weekly radio address to warn the nation of the potentially dire impact of Ryan’s budget on K-12 funding.

The Ryan plan, which has been approved twice by the U.S. House of Representatives, would result in a $2.7 billion cut to Title I grants for disadvantaged students. That cut alone could result in 38,000 job losses, the White House reported.

“That’s backwards. That’s wrong. That plan doesn’t invest in our future; it undercuts our future,” said President Obama. “If we want America to lead in the 21st century, nothing is more important than giving everyone the best education possible—from the day they start preschool to the day they start their career.”

Do those numbers sound familiar? They should, if you happened to be at a hearing of the House Appropriations panel that oversees K-12 spending. U.S. Secretary of Education Arne Duncan pointed to the same numbers, calling them “disastrous” for education.

The estimates are based on a White House analysis of the Ryan budget, which assumes that it would cut non-defense discretionary spending by almost 20 percent starting in fiscal year 2014 (which starts on Oct. 1 of next year, for your non-green-eye-shade types.)

Of course, Republicans have questioned the administration’s analysis. They point out that, while the Ryan plan does include some big reductions to domestic discretionary spending—the big broad budget category that includes education—it doesn’t actually say just what the cuts to individual programs would be.

The White House is assuming that Congress would just cut every program equally—which would be unusual, particularly when it comes to programs like special education that have a lot of fans in the GOP, as well as among Democrats).

But it’s also tough to make the case that K-12 would come out unscathed under the Ryan plan, senior White House officials told reporters yesterday. “It’s a fair assumption that you can only get to these levels of cuts in certain ways,” one aide said.

Added another, “Any time they want to detail exactly where they’re going to cut these programs, we’d be happy to take a look at that.”

White House officials argue that schools can’t really afford to get hit with big reductions in federal aid right now, since they’re still struggling to get out from under the recession. They’ve written an 18-page report detailing the impact of cuts at the state and local levels, including a 4.6 percent growth in class size between 2008 and 2010. And they argue that 300,000 educator jobs have been lost since the end of the recession.

And of course, they highlight the President’s plan to provide $25 billion to stave off teacher layoffs, which hasn’t gotten through Congress.

Of course, Republicans would argue that, in order to spare education, the White House would have to agree to cut entitlements, raise taxes, or cut other programs, including the military.

I’m sure we’ll hear way more about this debate as the presidential election heats up—and the big, fiscal cliff approaches.