For those on the right, complaints about "liberal bias" in the academy are now so reflexive--and so convenient--that it would take a great deal more than a "token effort" to silence them. My strong suspicious is that such an effort would just be met with escalating demands, which would be difficult to resist, since the initial "token" effort in essence conceded the justice of the underlying complaint.

Inside Higher Ed also covered this, but makes it sound like Alexander was addressing ideological diversity, which of course is different from intellectual diversity (however one might define that) and pedagogical diversity (by which, K.C., I'm assuming you mean teaching, say, for us historian folk, a variety of methodologies for teaching history). From Inside Higher Ed:

But several commission members said that they were surprised (and somewhat dismayed) that the senator had included among his top six priorities for the commission that it seek to rein in the “growing political one-sidedness” and “absence of true diversity of opinion” on most campuses, which he called “the greatest threat to broader public support and funding for higher education.”

“There is more to this charge of one-sidedness than the academic community would like to admit,” Alexander said. “How many conservative speakers are invited to deliver commencement addresses? How many colleges require courses in U.S. history? How many even teach Western Civilization? How many bright, young faculty members are discouraged to earn dissertations in the failure of bilingual education or on the virtues of vouchers or charter schools?"

Somehow I was unaware that teaching U.S. history is a conservative thing to do.

It sounds like Alexander implied that we need a political litmus test in faculty hiring decisions in order to ensure broad public support for higher education. I find that problematic on all sorts of levels.