Light's proposal: Congress should create a federal commission to draw up reorg/efficiency plans for the U.S. government. The key rule that legislators need to include: those plans would be submitted to congress for an up-or-down vote, with no amendments allowed. (This is how Congress decided which military bases to shut down.)
To understand why this is A Good Idea, consider the concept of "political slack" that Bryan explores in The Myth of the Rational Voter. In my words: politicians have some amount of slack to ignore their constituents' wishes without being punished at the ballot box. (Many things can affect the amount of slack a politician has.)
They can use that slack in two primary ways:
1) To engage in corruption, malfeasance, cronyism, etc.
2) To implement sensible policies that their constituents aren't sensible enough to support.
Zakariah doesn't use the term "slack," but in The Future of Freedom he makes a very similar argument to Caplan's: democracy (a.k.a. majority rule) often results in outcomes that are decidedly less than sensible--that are in fact often directly contrary to the ideal of constitutional liberalism. (Think: Hitler. Hamas.) And he suggests the very type of commissions-with-up-or-down-votes that Light is proposing. It is a means of giving politicians the right kind of slack: the kind that tends to result in sensible decisions.
Since the tools of malfeasance and corruption are not in the legislator's hands, but rather in those of their assigned commissioners, legislators have less opportunity for special dealing. And they can go along with a commission's sensible-but-unpopular policies with limited backlash, because they can point their fingers at the commission. But--this is a democracy--they still have ultimate yea-or-nay authority, and responsibility to their electors for that choice.
Light points to the Department of Homeland Security as the kind of mess that results when legislatures attempt to actually craft re-orgs themselves. It's like trying to write a novel via amendments and voice votes.
I for one see Light's proposal as a potential way out of the eternal conundrum: do we trust the vote of the people and the wisdom of the masses (or their elected representatives)--despite their frequently demonstrated lack of wisdom? Or do we assign philosopher kings and subvert ourselves to them?
How about: trust the people to select the representatives, who then assign philosopher kings (temporary duty only)? The representatives then vote on whether those philosophers' proposals are so wise after all.
And let the people decide whether their representatives are good judges of the philosophers' wisdom.