THey're not investigating the possibility that the WH may have misled the nation. They're trying to gin up the appearance that the WH misled the nation, and they're abusing their positions on the committee to do it.
What they're doing is EXACTLY what they've falsely accused the president of doing: Manipulating intelligence to further their political goals.
How do you differentiate between the two perspectives (investigation versus witchhunt)?
Precisely!
The Dems also are pretending that concerns about the danger Iraq's WMD posed were just invented by President Bush in mid-2002. In fact, the Bush 41 and Clinton administrations, the United Nations and all of their inspection teams, the British, Iranians, Saudis, Kuwaitis and other countries all had exactly the same concerns for all of the 15 or so years before. The Dem senate passed and Bill Clinton signed the Iraq Act of 1998 that made regime change in Iraq the policy of the United States and spelled out our concerns about his WMD. So if any intelligence was faulty, whose was it and when? Only when the Dems answer that question will I even entertain the notion of taking them seriously now.