Reports circulated yesterday that President Obama had reached an agreement with House speaker John Boehner (R-OH) and Sen. Joseph Lieberman (I-CT) to not only sustain the DC school voucher program for another few years but to eliminate the legislative cap on student enrollment—theoretically allowing it to grow without limit. Based the program’s performance to date, this would dramatically improve the graduation rate city-wide, likely boost performance academically, and save hundreds of millions of dollars from the bloated DC K12 budget.

But I didn’t write about it, because I didn’t believe it. Sure enough, later in the day, Secretary of Education Arne Duncan offered a clarification. Far from allowing unlimited growth in the program, the president only intended to allow another 85 students to participate—and still opposes the program in principle.

There is simply no way—no way—that President Obama could support an unlimited expansion in this successful, fantastically cost-effective education program. If he did, he would demoralize the most powerful force within the Democratic Party, the teachers’ unions, in the run-up to this fall’s election. Clearly he has no intention of doing that, given his recent advocacy of using federal dollars to grow the public school workforce (despite the fact that public school employment has already grown 11 times faster than enrollment over the past four decades).

We have a president who, for political reasons, cannot throw his full support behind the only federal education program in the nation’s history that is constitutional, successful, and cost-effective.