Jefferson Beauregard Sessions III has been this nation's attorney general for a year now and, as 2018 gets underway, he is finally getting serious about the war on drugs.

No, not about the opioid crisis that is claiming lives from big cities to tiny towns across the country.

No, not about the fentanyl scourge, an additive to heroin that vastly increases the drug's deadly danger.

No, Sessions last week decided to roll back previous Department of Justice guidance for U.S. Attorneys to encourage them to prosecute the use and production of legal marijuana.

Twenty-nine states and the District of Columbia have passed laws legalizing marijuana, some for medical use and others for recreational use. More states are expected to take action this year.

Pennsylvania is taking its first big steps after the state's General Assembly, in a rare show of bipartisanship, approved the use of medical marijuana. The first 435 state registration cards were mailed to doctor-certified patients in the last week of 2017 for a program that has received about 10,000 applications.

In New Jersey, which already has legal medical marijuana, Gov.-elect Phil Murphy will be sworn into office next week after campaigning last year on a promise to fully legalize the drug for recreational use.

Speaking of campaign promises, President Trump vowed at least three times while he was campaigning in 2015 and 2016 that he would leave marijuana policy up to the individual states that passed legislation.

"I'm a states person," Trump said in a July 2016 radio interview in Colorado, the first state to legalize marijuana for recreational use. "I think it should be up to the states, absolutely."

Trump clearly isn't interested in keeping that promise. He's too busy anyway, tweeting to reassure the nation that he is still mentally competent to do his job.

So to Congress we must go. And there we find encouraging signs. Some of the most interesting congressional pushback Sessions received last week came from fellow Republicans.

U.S. Rep. Ryan Costello, a Chester County Republican, is now circulating a letter among his colleagues, looking for co-signers to object to Sessions' moves.

We should know by next week if Congress is serious about this. A three-year-old provision, known as the Rohrabacher-Blumenauer Amendment, protects the use and production of medical marijuana.

It's part of the legislation to continue funding the federal government, which expires Jan. 19.

This is, by the way, an election year for every member of the U.S. House.

A Gallup poll in October found that 64 percent of Americans think marijuana should be legal, a record-setting result in a poll that has been asking that question since 1969. That includes 51 percent of Republicans, a nine-point increase from 2016.

U.S. Sen. Cory Booker, a New Jersey Democrat, introduced legislation in August to legalize marijuana. Congress could put that to a vote to see if there is a national appetite for legalization.

At the very least, Congress should protect the rights of states that legalize marijuana for medical or recreational uses.

That would free up Sessions and the Department of Justice to focus on the real danger from drugs — opioids and fentanyl.