Oregon came ever so close to passing a 2014 ballot measure that would have required the labeling of genetically modified foods.

The labeling effort here was led by progressives—the liberal wing of the Democratic Party who propelled U.S. Sen. Bernie Sanders (D-Vt.) to an easy victory over former Secretary of State Hillary Clinton in the May 17 Oregon primary.

Big agriculture and chemical companies defeated Measure 92 in 2014—but only by about six one-hundredths of a percent, a margin that came after a recount.

Part of what the "no" side said was they didn't want a patchwork of regulations with each state taking a different approach to labeling. They also defeated GMO bills in California in 2012 and Washington in 2013.

Now, a bill that is aimed at setting a national standard and is backed at least in part backed by the food industry and companies such as Monsanto that spent heavily to defeat the Oregon measure, is moving in the U.S. Senate.

Two of the measure's loudest opponents? Sanders, and the only senator to endorse his presidential bid, U.S Sen. Jeff Merkley (D-Ore.) both of whom say the bill senators approved by a 65 to 30 vote on July 7 does too little for consumers.

Critics like Senator Bernie Sanders, an independent from Vermont, say the bill’s vague language and allowance for electronic labels for scanning could limit its scope and create confusion.

“When parents go to the store and purchase food, they have the right to know what is in the food their kids are going to be eating,” Sanders said on the floor of the Senate ahead of the vote.

He said at a news conference this week that major food manufacturers have already begun labeling products with GMO ingredients to meet the new law in his home state.

Another opponent of the bill, Democratic Senator Jeff Merkley of Oregon, said it would institute weak federal requirements making it virtually impossible for consumers to access information about GMOs.

The bill now moves to the House of Representatives, where Reuters says it is expected to pass.