I hope John Edwards will support hearings. I know that Barack Obama has already declared he is against impeachment, but it is not for the senate to decide this question now. What is to be done is after investigations if there are found to be high crimes and misdemeanors which deserve conviction and removal from office, the house of representatives will pass articles of impeachment, and then prosecute it in the senate.
This is how the Clinton impeachment went, in that case there was no conviction in the senate. I think the fear of many is that an impeachment today might similarly fail if the Republicans simply hold firm against conviction no matter what.
My approach is to discredit the administration publicly for its high crimes and misdemeanors and build the case, so that the popular support for impeachment and removal will become so strong and obvious that the only way the Republicans can resist it is to sacrifice their own political careers.
And these are people with many skeletons in their closets, too.