The GOP downplays policy solutions to prevent school shootings. Here’s one idea.

Sen. Dianne Feinstein (D-CA) plans to introduce a bill that would raise the minimum age to purchase rifles from 18 to 21.

Under this proposed legislation, it would make it more difficult to purchase military-style assault weapons such as the AR-15 that was used by 19-year-old Nikolas Cruz, who is suspected of killing 17 people and injuring 15 others in a Florida high school last week.

The incident is the 18th school shooting and 40th mass shooting of 2018. And the weapon chosen by Cruz is the same type of assault rifle that’s been used in other similar tragedies.

Currently, federal law allows licensed gun sellers to sell long guns — including assault rifles — to individuals 18 years or older. You must be 21 years or older to purchase handguns.

“This policy is dangerous and makes absolutely no sense,” Sen. Feinstein said in a statement.

“If you can’t buy a handgun or a bottle of beer, you shouldn’t be able to buy an AR-15. This is common sense, and I hope my Republican colleagues will join me in this effort.”

Last fall, following mass shootings in Las Vegas and Texas, Feinstein along with other Senate Democrats introduced a bill to ban assault weapons and a device that would allow semi-automatic weapons to simulate automatic fire — allowing a gun to fire more bullets more quickly.

In the wake of the tragedy at Marjory Stoneman Douglas High School in Parkland, Florida, some Republican lawmakers, however, have argued that there is no policy solution to stop a similar event from happen again.

Florida Sen. Marco Rubio (R) — who received more than $1 million from the National Rifle Association during the 2016 election — said in a speech on the Senate floor the day after the high school shooting: “The struggle up to this point is that most of the proposals that have been offered would not have prevented, not just yesterday’s tragedy, but any of those in recent history.”

Meanwhile, in a speech to a sheriff’s convention in Washington on February 15, Attorney General Jeff Sessions said all that needs to be done is to simply enforce the laws that already exist. “It is not good if we got gun laws that say criminals can’t carry guns and they never get enforced,” he said. “So we intend to enforce our laws.”

This, however, wouldn’t have stopped Cruz, who is reported to have bought the gun legally — he had no criminal record and was of legal age to buy a military-caliber weapon. In Florida, the law only prohibits “furnishing weapons to minors under 18 years of age or persons of unsound mind.” While there is a three-day waiting period for buying a handgun, there is no waiting period for long guns.

When it comes to unlicensed gun dealers, however, the rules are even weaker. The minimum age is 18 when buying handguns and there is no age restriction when it comes to long guns.

As law professor Adam Winkler and pediatrician Cara Natterson explained in a 2016 Washington Post op-ed: “This has the perverse effect of forcing young people to buy handguns from sellers who — because they aren’t licensed — don’t have to conduct background checks.”

They also explained that people under the age of 25 “are responsible for a disproportionate amount of America’s gun violence,” including nearly 50 percent of all gun homicides.