It might have stopped Obama but - in all fairness - Bush wouldn’t have survived question time either. He wasn’t quick enough with his tongue or his wit. Question time has it’s advantages but it tends to elevate people who can make witty comebacks over people that are actually serious thinkers with slower tongues. Especially in the modern media age.
0, Bush, Churchill and Brown are great examples to use to test this hypothesis. Also, Question Time would be exactly the right place to ask about the birth certificate.