A handful of Democratic lawmakers are optimistic that Congress can pass legislation to ease federal restrictions on legal marijuana businesses.

The Democrats said they would seek to add their measures to broader legislation, such as the farm bill expected to move through Congress this year.

They said their bills would have little chance at moving on their own, but that they could get to President Obama’s desk if they are tucked in bigger bills.

“I think there's an opportunity with lots of moving pieces in Congress,” said Rep. Earl BlumenauerEarl BlumenauerSenate candidate Gary Chambers discusses his opposition to criminalizing marijuana Lobbying world Congress to take up marijuana reform this spring MORE (D-Ore.). “These are relatively minor technical adjustments, and in times past, things like this would find their way to be part of larger pieces of legislation.”

Blumenauer plans to introduce legislation that would change tax law to allow state-licensed marijuana businesses to deduct their business expenses from their federal taxes as other businesses do. He said existing laws continue to limit emerging small businesses.

He and several other lawmakers attended a press conference on Wednesday that was attended by more than 30 people who work in the cannabis industry. Democratic Reps. Jared Polis (Colo.), Barbara Lee (Calif.), Ed Perlmutter (Colo.) and Denny HeckDennis (Denny) Lynn HeckExclusive: Guccifer 2.0 hacked memos expand on Pennsylvania House races Heck enjoys second political wind Incoming lawmaker feeling a bit overwhelmed MORE (Wash.) also attended.

More and more states have liberalized their marijuana laws in recent years, with Colorado and Washington both legalizing the recreational use of marijuana.

Twenty-one states and the District of Columbia have passed laws that exempt the use of marijuana for medical purposes from criminal liability, Perlmutter said at the press conference.

The Colorado lawmaker has offered a measure to allow businesses to open bank accounts and end the current cash-only operation under which medicinal marijuana businesses operate. Under current law, banks could be prosecuted for allowing marijuana-related businesses to open bank accounts.

“Because marijuana remains illegal as a substance covered under the federal controlled substances act, individuals who grow, possess, use, sell, transport or do business with those businesses remain subject to federal criminal prosecution,” Perlmutter explained.

The lawmakers want marijuana-related businesses to be able to open legal bank accounts and operate without fear of federal forfeiture of property.

Blumenauer noted that marijuana dispensaries in Oregon and other states with liberalized laws can’t expand their companies due to outdated federal regulations that bar them from expensing normal business costs, such as expanding or remodeling facilities.

Perlmutter noted that it was key for lawmakers concerned with moving the measures to talk with the GOP leadership.

"This is a serious issue where 21 states have a different view of the use of marijuana than the laws on the books for the federal government. So our job is to speak with the leaders, really explain well, the conflict and not surprise them," Perlmutter said.