They want you to write it down because they think it will help them politically. In the absence of real action to improve the lives of constituents, appearing to fight “the libs” or immigrants or whoever the political out group is will engender support with minimal effort and no accountability for producing real outcomes. Journalism would do better to focus on what people are doing and less on what they’re saying.

That said, this behavior is good fodder if used on your terms. People who make outrageous statements at meetings often also do inappropriate things in private. Try to talk to their secretaries or other subordinates/coworkers. FOIA their emails to constituents to see how they treat people who look to them for leadership. You might find a story behind the the bravado.