CNN interrupted its broadcast of the Republican National Convention Monday after a speaker attacked President Joe Biden despite the Republican Party’s promise of a “unity theme.” After airing several minutes of former Yammer CEO David Sack’s speech, CNN suddenly cut to host Jake Tapper. “All right, that’s David Sacks, the founder and CEO of Yammer, giving a message focused a lot on foreign policy,” Tapper explained. “Some interesting language in that speech: senile, sleepy, demented, a reference to chants of ‘eff Joe Biden.'” Want more breaking political news? Click for the latest headlines at…