21 states plus the District of Columbia currently allow medical marijuana. Legislation is pending in an additional six states to do the same.

The amendment would not prevent the feds from going after those who are not in compliance with state laws. (Who determines compliance? The feds, of course.)

From Rohrabacher's press release:

“Patients and providers currently run the risk,” said Rohrabacher, “of having a federal SWAT Team-like police force raid their home or their place of business because of consumption of a plant. The militarization of the police force in order to prevent grandma from smoking an herb that will ease her pain during her last days on this earth is the type of thing that ought to make every conservative shudder.

“The harassment from the Drug Enforcement Agency,” he continued, “is something this body [Congress] should not tolerate. Businesspeople who are licensed and certified to provide doctor-recommended medicine within their own states have seen their businesses locked down, assets seized, and customers driven away.”

Senator Patrick Leahy raised this issue at the Senate Judiciary Committee last September:

“It is important, especially at a time of budget constraints, to determine whether it is the best use of federal resources to prosecute the personal or medicinal use of marijuana in states that have made such consumption legal,” Leahy said. “I believe that these state laws should be respected. At a minimum, there should be guidance about enforcement from the federal government.”

Since the feds claim their existing policy targets those who are not in compliance with state law, I'm not sure this would have much effect. Plus, it's not enough. What is needed is a federal law that decriminalizes all personal use and possession of marijuana (not just medical), removes marijuana from the list of controlled substances, disallows forfeiture for marijuana growers and sellers acting in conformity with the laws of their state, repeals mandatory minimum sentences for marijuana offenses and leaves the regulation of marijuana to the individual states.

The full text of H.R. 4660, the Commerce, Justice, Science, and Related Agencies Appropriations Act, 2015, as passed by committee on May 8 and introduced for consideration by the full House is here. The House Report accompanying the budget bill is here.

DOJ's full budget and summaries are here.