evidence: As the gravity of the situation sank in Saturday night, over-the-top rhetoric was on hold, replaced by bipartisan condemnation of political violence and calls to cool things down. In a statement, Biden condemned political violence and called the attack on Trump "sick," while his advisers halted television advertising and put active campaigning on hold. [...] The presidential historian Tim Naftali said on CNN that there have been other cycles of violence against presidential candidates in US politics — frequently at times of social change, including 1968, when Robert F. Kennedy and Marin Luther King, Jr., were shot. He said political violence is "bred in the bone" of the country.