and rachel, tomorrow, of course, the first day of this trial and the first several hours expected to center around this debate of whether a senate trial of a former president is actually constitutional. this, of course, has never been done before, an impeachment trial of a former president, but democrats tonight are trying to make the argument that there is precedent here. >> reporter: yeah, david, and democrats had to go back nearly 150 years to the impeachment trial of 1876. it was held at the time for the secretary of war who had already left office. democrats say that sets precedent. but still, those house impeachment managers face a significant challenge. already, 45 republican senators have said the trial itself is unconstitutional, david. >> we'll be watching that right along with you, rachel. in the meantime, you are also following a breaking headline just as we're on tonight out of georgia. the secretary of state there officially launching an investigation into the former president, whether he violated the law when he made those phone calls pressuring elections officials. of course, we all heard that