This is a long two part video, so I'll sum it up briefly.
This discussion is not focused on crimes Bush or Cheney may or may not have done. In fact it's conducted without any bias towards Democrats or Republicans.
One of the discussers helped get Clinton tried for impeachment and still thinks he did the right thing. However he also points out that it's even more necessary for impeachment hearings to be conducted on Bush and Cheney.
The basic point is that the powers that Bush and Cheney have improperly acquired for themselves can be passed on to their successors. Such a precedent without it being challenged will mean the next president can easily assume the same imperial/monarchical powers improperly. This would be dangerous no matter who the next president is.
Therefore, even though Bush and Cheney will only be in office for 18 more months, it's necessary to at least have the hearings and challenge the extra powers they now have. The discussers even hope that Bush and Cheney simply admit they were wrong and give up their extra powers without resigning so that an impeachment will not be necessary.