U-Turn Quotes
When Donald Trump was running for the presidency as the Republican nominee, a large proportion of the party stalwarts were very unhappy with Trump's often extreme positions, which not only offended them put turned off most voters. After much negotiating the Republican leaders thought that they has an agreement whereby trump would pivot on the most egregious and unpopular positions. However many Republican leaders like Flake were not happy with Trump's pivoting technique.
Politics is peculiar in the sense that most things are seen as black or white. In most other areas of human endeavor, people change, not because the old way was incorrect, but because the new way might be better. Einstein’s Theory of Relativity did not totally invalidate the physics of Issac Newton; it just improved on it in some areas.
This quotation is one of the more famous examples of a mixed metaphor error—taking the image of mammals changing but using the “mid-flight” terminology which only applies to flying birds.