democrats blasting the republican-drafted road map as a cover-up, but managing to win an early concession from the republican leader. peter alexander starts our coverage >> reporter: tonight president trump is officially on trial. >> the senate will convene as a court of impeachment. >> reporter: both sides, house democrats who will prosecute, and the president's defense team arriving in the capitol, a dramatic scene on the senate floor. all 100 senators, the jurors warned not to speak. >> hear ye, hear ye, hear ye, all persons are commanded to keep silent on pain of imprisonment >> reporter: it follows a bitter clash over rules mitch mcconnell saying he was following the bill clinton impeachment model that allowed each side 24 hours to make its case. >> the process was good enough for president clinton and basic fairness dictates it ought to be good enough for this president as well. >> reporter: but democrats objecting to a key difference from the clinton rules, new limits that would force each side to make those