Scoop: Senate Dems line up behind Heinrich, Schumer's bump stock ban

Driving the news: Sens. Martin Heinrich (D-N.M.), Catherine Cortez Masto (D-Nev.) and Susan Collins (R-Maine) have picked up 20 new cosponsors for their Banning Unlawful Machinegun Parts (BUMP) Act since the ruling.

• Republicans are likely to object to Schumer's unanimous consent request to pass the bill.
• Even a single GOP objection would give Democrats the opportunity to paint Republicans as broadly against a ban that polls have shown is popular and was put place under the Trump administration — right after a string of mass shootings that left nine dead over the weekend.

Catch up quick: Bump stocks are attachments that allow semiautomatic rifles to fire bullets more rapidly. They were banned after a 2017 mass shooting in Las Vegas, in which a gunman opened fire on a music festival, killing 60 people and wounding 850 more.

• In its 6-3 ruling last week, the Supreme Court's conservative majority argued that bump stocks do not convert semiautomatic rifles into what the law defines as a machine gun.

The big picture: The Supreme Court's decision brings fresh attention to the debate over gun control ahead of the November election.

• Democrats are confident that voters, on balance, will reward any efforts at moderate firearms restrictions.

Between the lines: Two vulnerable Senate Democrats from battleground states President Biden won in 2020 — Jacky Rosen (D-Nev.) and Bob Casey (D-Pa.) — cosponsored the bill.

• By contrast, Sens. Sherrod Brown (D-Ohio) and Jon Tester (D-Mont.)— who are seeking re-election in states Trump twice won — have not signed on.
• Schumer's strategy of prodding Republicans to block the measure without a recorded floor vote could provide some cover for vulnerable Democrats from red states.