steal (someone's) clothes
To advance or appropriate someone else's ideas, policies, or agendas as one's own. Many believe the challenger is really trying to steal the incumbent's clothes and beat him at his own game.
steal someone's clothes
BRITISH, JOURNALISMIf a politician or political party steals another's clothes, they take their ideas or policies and pretend that these are their own. Instead, Labour has been allowed to steal the Conservatives' clothes by promising to involve the private-health sector. It would be stealing their political clothes — and few politicians can resist this opportunity.
steal someone's clothes
appropriate someone's ideas or policies. British informal