As with the last time he was elected Trump has vehemently criticised a policy of his predecessor, and then immediately adopted the same policy as his own on being elected.
He did it over bombing Syria if they used chemical weapons, and he’s doing it over Ukraine now, making it clear he intends to continue fully supporting them, while also pushing for a huge increase in military spending. Both policies he and his party were adamantly against and did everything they could to undermine while in opposition.