The Senate has to convict him after a trial, a trial in which evidence from both sides is presented. If Watergate is any indication, the whole affair will be televised. Any RINO who voted to convict on evidence that did not persuade the public would be committing political suicide. I am sure this is why the Republicans during Watergate confronted Nixon instead of actually going through a trial -- they did not want to take the risk of rendering a verdict.