In order to sit in the Senate Gallery during these debates you have to have a pass signed by a senator. The protesters were PLACED there.
That's why Code Pink protestors were always allowed in despite being recognized bt the out landish pink costumez, they had Congress members protection.
Bit of history as to when and why passes were instituted for security reasons.
Timeline of 1954 US House of Representives Shooting
On the morning of March 1, 1954, four Puerto Rican nationalists—Lolita Lebron, Rafael Cancel Miranda, Andres Figueroa Cordero, and Irving Flores Rodriguez—boarded a train from New York City for Washington, D.C. Since 1898, when the United States took control of Puerto Rico, the status of the island has been debated. Over time, three main viewpoints took shape concerning Puerto Rico’s relationship with the United States: territory, state, or independent nation. The nationalists who traveled to the Capitol supported the most extreme interpretation of the latter—one which called for violence to draw attention to their goal of complete Puerto Rican independence from the United States....(read more at link)
"Five Congressmen were wounded in the shooting, including Representatives Alvin Bentley of Michigan, Kenneth Roberts of Alabama, George Fallon of Maryland, Ben Jensen of Iowa, and Clifford Davis of Tennessee. Bentley, the most seriously injured remarked, “I next remember being hit with what felt like a terrific blow on the chest. I didn’t realize it was a bullet. It felt more as if somebody had taken a club and socked me on the chest and knocked the wind out of me.”
The four Puerto Rican nationalists—Lebron, Miranda, Cordero, and Rodriguez—were indicted, tried, and convicted in federal court for their actions. They received sentences ranging from 16 to 75 years in federal prison. More than two decades later, President Jimmy Carter granted clemency to the shooters. (Yet another reason to wish for an expedition departure of Carter to another plane)
The House shooting followed the 1950 assassination atempt on President Truman by...radical Puerto Rican Nationalists...read all about it.