Congress will return to Washington this week under new pressure to take action on gun control in the wake of the mass shooting at a Florida high school.

Lawmakers will have a range of potential policies to consider, as President Trump and others have put both new and old ideas on the table in an effort to curb gun violence.

It’s unclear which proposal – if any – will be able to overcome the thorny politics that have impeded past efforts to enact tougher gun laws in the aftermath of other mass shootings.

Conservatives and the powerful gun lobby do not support some of the ideas that have been floated, while even the least controversial measure has been stalled in Congress for months.

“I see Congress wanting to act now for the first time,” Trump told reporters Friday.

Here are seven gun proposals that are now in the mix following the deadly school shooting in Parkland, Fla.

Background checks

Trump has vowed to “strongly” push for strengthening background checks for gun purchases, with an emphasis on ensuring that the seriously mentally ill can’t acquire firearms.

The House already passed similar legislation last December, but it was paired with a contentious bill to allow people to use permits for carrying concealed weapons across state lines.

It’s also uncertain whether Trump would support expanding the current background check system, which would go a step further than the Fix NICS bill.

Sen. Pat Toomey (R-Pa.) is planning to revive a measure that failed to pass in 2013, which would have expanded background checks to cover sellers that have otherwise been able to skirt background checks, like online sellers and unlicensed gun show dealers.

Age limits

One proposal quickly gaining steam in Congress and some states would impose new age limits on gun purchases.

But the NRA still adamantly opposes raising the age limit, making it a tough sell in Congress – especially in the House.

“Raising the age is not going to solve psychosis,” NRA spokeswoman Dana Loesch told CNN on Friday.

Armed teachers

The most controversial idea that Trump has embraced is arming teachers and school administrators with guns in order to protect schools.

“When we declare our schools to be gun-free zones it just puts our students in more danger – well-trained gun-adept teachers and coaches should be able to carry concealed firearms,” Trump said Friday at the Conservative Political Action Committee conference.

An armed teacher would have “shot the hell out of” the gunman who killed 17 people at a Florida high school last week, Trump added.

“The president and others promoting arming teachers are delusional,” Michael Steele, former chairman of the Republican National Committee, wrote on Twitter. “Wake the hell up people. There was a uniformed, armed police officer on duty at Douglas H. S. and he did nothing. And you expect teachers to do his job?”