Senate Democrats have included universal background checks in the gun control package the Senate will debate next month, and Vice President Joe Biden hammered on the need for the measure on Thursday, saying most Americans support the measure.

“There’s no real debate” about expanding background checks, he said. “The only question is whether Congress will have the courage to do the right thing.”

Biden cited a survey by Mayors Against Illegal Guns that found 89 percent support for the background checks in 41 Congressional districts across the country, and 86 percent in 21 statewide polls.

A Quinnipiac poll released today found similar support, with 88 percent of respondents for background checks. The proposal had 83 percent support among Republicans and 96 percent support among Democrats.

But gun retailers strongly oppose the measure, according to a survey of 640 gun sellers by the National Shooting Sports Foundation released Wednesday. Eight-six percent of federally-licensed gun sellers said they don’t support universal background checks, and worry the proposal would result in unintended consequences for retailers.

Even more dealers said universal background checks would be ineffective, with 96 percent saying they won’t keep criminals from getting guns.

National Rifle Association members, which include over 4 million gun owners, also oppose the measure, according to the NRA’s own survey of its members.

But Democrats say the checks must be part of any new gun laws.

“I want to be clear: In order to be effective, any bill that passes the Senate must include background checks,” Reid said in a statement on Thursday.

Background checks currently apply only to licensed firearms dealers, but expanding the law would extend require them for sales between private citizens.