From Yahoo! News:

Paul Rosenzweig, who worked on the impeachment of President Bill Clinton and is now a senior fellow at the R Street Institute, a Washington think tank, said that “constitutionally, the Republicans have no argument,” and that their appeals to precedent were also “unpersuasive,” since the impeachments of both Clinton and, before that, Richard Nixon took place behind closed doors to some degree, at least in the initial stages. (Democrats have promised to eventually release transcripts of witness interviews.)

Rosenzweig said that Republicans’ best argument was political: that keeping the impeachment process cloaked in secrecy “doesn’t look fair.”