In the past, marijuana lobbyists have focused on reducing federal penalties for possession and sales of the plant. But Thursday's trip to Capitol Hill follows the legalization of recreational use of marijuana in Colorado and Washington State while medical marijuana is now legal in 20 states -- and in the District of Columbia, the Washington Post reported.
Celinda Lake, a Democratic pollster, spoke at a briefing organized by the association. She said public support for legalization of pot is up, especially among young people.
"This is an issue that is absolutely at its tipping point," she said.
The association, less than four years old, now has about 550 members and a full-time lobbyist. This year, 55 people involved in the marijuana business came to Washington.
The group wants a change in tax laws that bar them from deducting ordinary business expenses. The association points out that Colorado collected $2 million in taxes on marijuana in January, when recreational sales became legal.