Verb
change sides (third-person singular simple present changes sides, present participle changing sides, simple past and past participle changed sides)
to change one's loyalty from one team or group to an opposing one
Synonym: switch sides
The politician may change sides so frequently as to find himself always in the majority, but most politicians have a preference for one party to the other, and subordinate their love of power to this preference. Bertrand Russell
Behind a leader there must be followers, but they should always be on the lookout for the main chance and ready to change sides if the current leader doesn't deliver. Mary Douglas
Badoglio’s envoys stated that the desire of their new government was to not only surrender but also to change sides and fight the Germans. Source: Internet
Bradbury, pp.134, 136. Possibly this illness was the result of his imprisonment the previous year, but he finally recovered and travelled north to raise new forces and to successfully convince Ranulf of Chester to change sides once again. Source: Internet
Stephen travelled north to raise new forces and to successfully persuade Ranulf of Chester to change sides once again. Source: Internet
Both parties had internal divisions and very little ideology separated them, allowing Colorado and Liberal members to change sides whenever it proved advantageous. Source: Internet