clean sweep

noun

a victory in which one side or team wins every game, contest, etc.
a complete change in something
an election when a candidate or party achieves an overwhelming or complete victory, winning in all or almost all districts or precincts

A complete or overwhelming victory, especially one in which all or almost all possible electoral contests are won.
“In November 1928, as the beneficiaries of this revulsion, the Liberals made a clean sweep of every seat on the borough council.”
“By 1991 his constituency had made a clean sweep of all twelve local council seats, that's in part to Nellist’s high-profile efforts.”
The winning, by a person or team, of all the possible possible prizes, games, rounds or contests, etc in a competition, season or series.
“Scott Russell, who had sewn up the Yokohama 750cc Supersport championship earlier in the year, completed a clean sweep of the series races with his ninth victory in Miami.”
“He achieved a clean sweep winning four professional majors in a span of 294 days.”
A thorough change of policies, personnel or objects, removing or replacing all or almost all of that which existed previously.
“These were unfortunate selections and Mr. Quincy, who had the consular appointments in charge, so made an almost clean sweep in that branch of the service, removing Republicans and putting Democrats in with “unprecedented vivacity.””
“[In 1951] Colby had an almost clean sweep of his closest official advisors.”