Earlier this year, the Massachusetts Office of Campaign and Political Finance received an unusual inquiry from a state lawmaker: Could campaign funds be used to purchase bulletproof vests, gas masks and pepper spray?

It was a question the independent state agency, which regulates political spending and hands down advisory opinions on campaign finance issues, had never been asked before.

Yet in the weeks and months after the Jan. 6 U.S. Capitol riot, it is the kind of query that is surfacing with regularity both in Washington and in state capitals across the country. Alarmed by a growing number of threats, harassment and scenes of violence at government buildings, lawmakers in both parties are seeking clarity from election agencies on whether they can spend campaign dollars and taxpayer money on security and personal protective equipment — everything from body armor to panic buttons at home.

“Threats have an impact,” said Michigan Democratic state Rep. Kevin Hertel, who noted that threats against state legislators […]