They don’t budge. See the comparisons from 538 below. Unlike every other president’s poll numbers, Trump’s barely change in response to events. Why don’t people update their beliefs–pro or con–in response to his latest triumph or outrage? Possible answers:
- Nothing of significance has happened. Bush benefited from 9/11 and was hurt by the Iraq war, and Obama was hurt by continuing economic distress in the wake of the financial crisis. But not much has changed since Trump took office.
- People no longer tell the truth to pollsters, or polling results have become noisier because people no longer answer the phone. Something about how 538 aggregates poll results?
- People’s political commitments have become more tribal, and so they refuse to adjust their beliefs in response to information.
If #3 is right, then the Democrats should not expect that impeachment hearings will generate political support for impeachment, and would be wise to resist the temptation.