What is one reason a legislator may agree with the issue that H. R. 3999 addresses?

The reason will be "Addresses seems to be an effort to endorse a bit of legislation that limits the selling of weapons across the U.S".

Explanation:

H.R. 3999, a public corruption code regulation bans the production, ownership, sale of semiautomatic firearms throughout the U.S. The law doesn't require a person to do otherwise. If it breaks the rule, the person may be fined or sent to jail.This bill has been established to implement tighter gun regulation in America, after several horrific fatal shootings in high schools and everywhere else.