Political circus or lynch mob?

To anyone who closely follows American legislative happenings at the federal level, one of the more entertaining phenomena would undoubtedly be House and Senate hearings. Legislative hearings are organized by committees in either houses to inform legislation, investigate public policy affairs, question nominated officials etc.

While most hearings are run-of-the-mill bureaucratic affairs, some pertaining to emotion-laden issues offer very entertaining political histrionics. Some instances from the recent past were those where legislators questioned the big three auto-makers (where the latter were whipped for flying their private jets to Washington) or the numerous hearings following the credit crisis involving bankers, policy-makers, federal officials etc.

On these public-passion-generating topics, it is clear that the purpose of the committee-members is not to investigate or inform themselves, but simply use the platform for political posturing and venting of public emotion. These hearings sometimes turn brutal, with committee members heaping scorn and sarcasm on the questionee, barely maintaining parliamentary decorum.

Case in point was the grilling of Tony Hayward, BP CEO, by the US House Energy and Commerce Subcommittee. There are plenty of sources where the entire hearing can be perused, but a representative snapshot is this one below (link to picture source) of Rep. Steve Scalise of Louisiana brandishing a picture of an oil-soaked pelican, apparently to exhibit the tragedy of the damage caused by the Deepwater oil spill.

One wonders what purpose dramabaazi like this fulfills in what is supposed to be an investigative hearing besides shaming the 'defendant' in front of a millions-strong audience.

The affair is analogous to a lynch mob because the purpose of mobs baying for blood is exactly what motivates such passionate legislative hearings - the venting of public anger against a perceived crime. As it goes with mobs, facts take a back seat.

While the political drama such hearings provide is certainly entertaining, it does bring to mind the question whether public shaming like this is constitutional. If BP is indeed found guilty of civil/criminal defaults as the result of a judicial process, they will certainly end up paying the due penalties. Is this scapegoating/humiliation then a subversion of the judicial process, and does it constitute "cruel and unusual punishment" (or worse, because the crime has not yet been proven)?