Political violence jolts the US once again - with a familiar response

But Trump's response since the shooting has focused largely on removing obstacles to constructing a massive ballroom at the White House where the mansion's east wing once stood.

On Sunday, Trump posted on social media that Saturday's incident was "exactly the reason" he wants the ballroom.

In a letter to the historic preservation group that filed a lawsuit challenging the legality of the ballroom, Assistant Attorney General Brett Shumate said the structure would ensure the president's "safety and security".

"Your lawsuit puts the lives of the president, his family and his staff at grave risk," he wrote.

Several Republicans in Congress promised to introduce legislation explicitly authorising the ballroom.

"The ballroom will be a solution for this," Speaker of the House Mike Johnson, referring to the correspondents' dinner, said in a Monday interview on Fox News. "It'll be a safe environment to do events like that."

It's unclear if the White House Correspondents' Association, which organises the fundraising dinner, would want the president – traditionally an invited guest – to host the annual event. And even with a fortified ballroom at their disposal, presidents typically travel around America for speeches, fundraising events and other public appearances.

A ballroom by itself will not fully address safety concerns raised by Saturday's incident. Those concerns include how a man was able to bring weapons into a building hosting a president and top government officials, whether the security perimeter set out by the US Secret Service was sufficient, and whether guests in other parts of the hotel should have been screened.

According to a senior administration official, White House Chief of Staff Susie Wiles is convening with Secret Service officials early this week to "discuss protocol and practices for major events" involving the president – including US 250th centennial celebrations this summer.

After the Butler shooting at a fairground near Pittsburgh, Trump drastically curtailed his outdoor rallies. Since becoming president, he has preferred appearances at secure military bases, and speeches and roundtables in smaller venues. Larger public appearances have moved to indoor arenas, where it is easier for the Secret Service to screen attendees.

With the midterm elections looming, however, Trump will be pressed to hit the campaign trail to encourage his supporters, who often stay home when he is not on the ballot, to turn out to vote.

A bunker mentality may make for a safer president. But it could come at a political price.