"We will look back at this debate potentially as the beginning of the end because he didn't come across as prepared," Frank Luntz said. "I don't think he captured the tone of the audience."
Tuesday's congressional testimony will feature three witnesses who listened in on Trump's July 25 phone call with Ukrainian President Volodymyr Zelenskiy.
The acting chief of staff is expected to be a no-show, falling in line with several other officials who were ordered by the president not to cooperate with the investigation.
Perry tells CNBC that President Trump won't face full impeachment proceedings.
U.S. Secretary of Energy Rick Perry spoke to CNBC's "Squawk on the Street" on Monday following a series of drone attacks on Saudi Arabia's oil facilities, which caused the largest disruption to the world's oil supply in history.
Perry says it's too soon to say whether the U.S. will need to use its emergency crude reserves to offset the surge in oil prices.
"The climate is changing. Are we part of the reason? Yeah, it is. I'll let people debate on who's the bigger problem here," says Perry.
The U.S. opposes Nord Stream 2, arguing the pipeline would allow Moscow to bypass Ukraine and use energy as a weapon against its neighbors.
President Trump signals the U.S. won't stand for Tehran's "support of terrorism" and threats to restart its nuclear program, Energy Secretary Rick Perry tells CNBC.
"There is no truth that Secretary Perry is departing the administration any time soon," a Department of Energy spokesperson said.
The Trump administration has authorized seven nuclear energy technology transfers to Saudi Arabia, angering many lawmakers.
CNBC's Hadley Gamble reports on a new story from Reuters that Energy Secretary Rick Perry secretly approved several deals for companies to sell nuclear power technology to Saudi Arabia.
Energy Secretary Rick Perry has approved six secret authorizations by companies to sell nuclear power technology and assistance to Saudi Arabia, according to a copy of a document seen by Reuters on Wednesday.
Perry's stance clashes with comments made by other members of his administration — including his boss, President Donald Trump.
U.S. Secretary of State Mike Pompeo and Secretary of Energy Rick Perry join CNBC's Brian Sullivan to talk about energy policy, petro diplomacy and the situation in Venezuela.
U.S. Secretary of State Mike Pompeo and Secretary of Energy Rick Perry join CNBC's Brian Sullivan to discuss America's energy policy and Europe's energy security.
The U.S. will continue to do whatever it takes to rid Venezuela of disputed leader Nicolas Maduro, Secretary of State Mike Pompeo told CNBC.
U.S. Energy Secretary Rick Perry sits down with CNBC's Brian Sullivan at CERAWeek to discuss trade, the energy sector, exports and more.
The former Texas governor, whose Cabinet role makes him twelfth in the presidential line of succession, will sit out the event, which attracts those at the top levels of government to gather in a single room.