Criminalize Fleeing from Immigration Enforcement Act of 2021 This bill revises the federal criminal offense involving flight from an immigration checkpoint or other law enforcement checkpoint at high speed in a motor vehicle. Specifically, the bill retains the existing prohibition on flight from an immigration or other law enforcement checkpoint, but it removes the qualifier that such flight must be at high speed in a motor vehicle. The bill also expands the scope of unlawful flight offenses to include flight from a law enforcement officer who is enforcing immigration laws. An unlawful flight offense is generally punishable by a fine, a prison term of up to five years, or both. However, an unlawful flight offense that involves high-speed flight in a motor vehicle is punishable by a fine, prison term of up to eight years, or both.