The Closing Bribery Loopholes Act amends federal bribery laws to provide a clearer definition of what constitutes an "official act" that is prohibited from being influenced by bribes. Under current law, prosecutors have struggled to prove bribery cases because the definition of official acts has been unclear and subject to court interpretation. This bill clarifies that official acts include not only individual decisions or recommendations by public officials, but also multiple related acts or a course of conduct working toward an official outcome, and that an official act is illegal to influence even if it ultimately fails to achieve the desired result. The legislation affects public officials and anyone attempting to bribe them or witnesses in federal cases. The bill does not specify new funding or implementation timelines, instead modifying existing criminal statutes to close perceived gaps that bribery defendants have exploited.