Today Rep. Dana Rohrabacher (R-Calif.) reintroduced his Respect State Marijuana Laws Act, a very short bill that makes the federal ban on cannabis inapplicable to people acting in compliance with state law. That simple approach essentially repeals marijuana prohibition at the national level, limiting the federal government's role to assisting states that continue to ban the drug. In that respect, Rohrabacher's bill goes further than the CARERS Act, which is limited to medical use of marijuana (except for the banking provisions).

The 2013 version of Rohrabacher's bill attracted 28 cosponsors, including six Republicans. This year the bill's 12 initial sponsors are evenly divided between Democrats and Republicans. The Democrats are Steve Cohen (Tenn.), Earl Blumenauer (Ore.), Dina Titus (Nev.), Janice Schakowsky (Ill.), Jared Polis (Colo.), and Mark Pocan (Wis.). The Republicans are Rohrabacher, Duncan Hunter (Calif.), Don Young (Alaska), Tom McClintock (Calif.), Thomas Massie (Ky.), and Justin Amash (Mich.). Judging from their support for a federalist approach to marijuana policy, at least four Republican presidential contenders—Rand Paul, Ted Cruz, Jeb Bush, and Rick Perry—should favor Rohrabacher's bill as well. Chris Christie, not so much.

"Unlike other bills that address only some aspects of the conflict between state and federal marijuana laws," says the Marijuana Policy Project's Dan Riffle, "this bill resolves the issue entirely by letting states determine their own policies. It's the strongest federal legislation introduced to date, and it's the bill most likely to pass in a Republican-controlled Congress. Nearly every GOP presidential contender has said marijuana policy should be a state issue, not a federal one, essentially endorsing this bill."