How did caning of charles sumner increased sectionalism?

On May 22, 1856 at the US Senate, Representative Preston Brooks, who was a democrat from South Carolina, attacked fellow senator Charles Sumner who was a Republican from Massachusetts. Sumner was an abolitionist who walked with a cane. Brooks attacked him as retaliation for a speech Sumner had given just two days prior that criticized the people who still held slaves which included Brooks relatives.The beating was so severe that it nearly took Sumners life. This drew harsh criticism from the public when it came to expanding slavery in the US. It is considered the point where the breakdown of reasoned discourse in the country that eventually led to the Civil War.