What does "scorched earth politics" mean?

Context>>>>>>>>
"Party and politics will never come before the country I bled to protect—and would unquestionably do so again," the Army veteran said. "A President coercing a foreign government into targeting American citizens is not just another example of scorched earth politics, it serves as an invitation to the enemies of the United States to come after any citizen, so long as they disagree with the President. Embarking on an unprecedented effort to obstruct this inquiry doesn't make the facts any less true. Therefore I will vote in support of the two Articles of Impeachment."