Sen. Cory Gardner made his push to add an amendment to a popular criminal reform bill in the U.S. Senate all about states' rights. It's a cause close to the heart of Conservatives nationwide.

He did not make his push about the meat of the amendment: allowing pot businesses, which legally sell a Schedule 1 drug in Colorado, to use the U.S. banking system. 

Gardner billed the amendment to the First Step Act as a way to cut down on crime; if pot businesses are using banks, there's less chance for shady practices and money laundering; he billed it as a way to normalize payroll for pot shop employees and make the whole enterprise more transparent.

The Colorado Senator made his case on the Senate floor Tuesday afternoon. He posted his remarks to his YouTube page, again calling this a states' rights issue.

The amendment was killed by Sen. Chuck Grassley (R-Iowa) just minutes after Gardner began talking. Grassley is the chairman of the Senate Committee on the Judiciary and has been a U.S. Senator since 1981.

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"The package today that's on the floor, that's we're debating - talking about amending - shows the American people that bipartisanship remains alive in the U.S. Senate - leaders on both sides of the aisle and the White House should be commended..." Gardner said to begin his remarks.

His remarks are partly true: the STATES Act was first proposed by Gardner and Sen. Elizabeth Warren (D-Massachusetts) over the summer. And while it saw very little movement, Gardner's plan to attach it to the criminal reform bill was a way to get a bipartisan piece of legislation passed through the U.S. Senate.

It wasn't partisanship nor a member of another party that tanked his efforts. It was a fellow member of the GOP. 

Before Gardner even got to talking about the amendment - Grassley explained why he was objecting to the bill, citing its opposition to federal law.

"If there is an attempt to legalize [pot] across the country, we should have that debate and let Congress decide the issue instead of creating a backdoor to legalization," Grassley said.

He added that the criminal reform bill was a place where Congress should create reform for banks. He thanked Gardner for his efforts and said he respected him.

Grassley has a history of anti-marijuana leanings. According to the Des Moines Register, in 2015 the Senator voted against a bill that would have allowed marijuana to be rescheduled as a Schedule II drug. 

Gardner spoke for nine minutes after Grassley's objection, concluding by saying he will not give up the fight to allow pot businesses the use of the banking system.

After the amendment's failure, Gardner posted on Twitter that he was not giving up the fight to allow pot businesses to use banks. 

"Over 95% of the US population lives in a state where some form of marijuana is legal," the tweet reads. "This isn't a fluke, the American people have spoken and this is happening. My amendment to the First Step Act has been blocked, but I will not give up this fight."

It's unclear where Gardner will go next with the amendment. He could attach the STATES Act as an amendment to any bill, but it appears unlikely moving forward that his fellow Republicans are receptive to it.

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