Education Secretary Arne Duncan is keeping up his high-profile pressure campaign on states he deems unfriendly to charter schools.

This afternoon, in a conference call with education reporters (and some charter school groups), he explained once again that states that don’t allow charters to open and those that impose caps on the number of schools will be at a “competitive disadvantage” when he starts to dole out $4.35 billion in Race to the Top discretionary grant dollars later this year.

He wasn’t willing, however, to be terribly specific about how much weight he’ll assign to states’ charter friendliness. Only that “we’re going to have an absolutely simple, and transparent application process,” with “a clear series of questions and clear points assigned.”

He did say that those states still at work on improving their stance toward charters could have a crack at Race to the Top money next year because he’ll award grants in two rounds: the first with an application deadline of Dec. 1 of this year, and the second likely next spring.

So for states like Maine, where charter schools so far have lost their battle to open, and Tennessee, where restrictive enrollment policies and a 50-school cap are in place, there are a few extra months to improve their standing with Secretary Duncan.