Voter legalization of recreational marijuana in two more states plus the District of Columbia this week mounts pressure on the federal government to decriminalize cannabis — nudging America closer to a weed business boom, pot advocates and opponents agree.

A federal law banning marijuana sales remains the biggest blockade to the dawn of a national cannabis industry. That law causes many banks to avoid dealing with legal pot retailers, forcing weed entrepreneurs in Colorado and Washington to run cash-only operations — a daily danger, the owners say.

“But the direction voters are moving in is obvious, and with additional states it’s now harder to call Colorado and Washington 'experiments,’” said Derek Peterson, founder and CEO of Terra Tech Corp. The Irvine, California company focuses on local farming and medical cannabis — likely the first publicly traded company, Peterson said, to hold a medical marijuana license.

“These are the same voters who elect our federal lawmakers, which I think is the major reason you’re seeing such a quick and dramatic turnaround on these policies in Congress,” Peterson said.

In July, for example, the U.S. House voted in support of a measure to make it easier for banks to conduct business with legal pot shops and providers of medical marijuana. That bill has not yet cleared the Senate.

Tipping the scale?

At Seattle-based Privateer Holdings — which invests in the cannabis industry to acquire and create mainstream brands, like Leafly.com — Patrick Moen, a former DEA agent now on staff, says he remains cautiously optimistic that a federally reversal is “inevitable” given the latest votes.

"This is just another thumb on the scale with regard to the whole panoply of federal issues here,” said Moen, managing director of compliance at Privateer. “It represents the will of the people. Eventually, the federal government will catch up.”

But one more federal obstacle, Moen said, also must be removed: IRS tax code 280E, which bars companies from deducting expenses if their business dealings consist of “trafficking in controlled substances.” Under federal law, marijuana is a Schedule I drug, classified as such like heroin and ecstasy.

That’s where voter legalization of pot in the District of Columbia will be particularly meaningful to changing minds on Capitol Hill and in the White House, Moen said.

“It's right in their backyard. They’ll get to see firsthand, not only is legalization not harmful, but it’s actually beneficial to society,” Moen said. “And Congress will have the opportunity to potentially veto or override this (federal) legislation. So, we’re going to see, probably in short order, exactly how Congress feels about this.”