If you look closely at Trump's current core team, you'll notice an interesting reality: many key figures not only opposed him in the past but also openly criticized him.

The most typical example is Vice President JD. Vance. In 2016, he described Trump as America's "dangerous person" and even compared him to historical extreme leaders like Hitler, clearly belonging to the opposition camp at the time. But a few years later, he gradually shifted to support Trump's line, and now he is not only an important figure in the MAGA camp but also directly part of the power core, completing a significant transformation from opponent to successor team member.
Similarly, Secretary of State Marco Rubio. During the 2016 Republican primaries, the two were direct competitors, attacking each other, and their relationship was very tense. Rubio publicly questioned Trump's abilities and qualifications at that time. But as the internal power dynamics of the Republican Party changed, he gradually aligned with Trump on foreign policy and national security issues, and now he is one of the key members of his administration.
There is also Robert F. Kennedy Jr., whose background is even more unique. He originally came from the Democratic system and had long been critical of Trump. After running as an independent presidential candidate in 2024, he ultimately formed a political alliance with Trump and entered the government system. This change is not fundamentally a shift in stance but a typical reorganization of political alliances.
Elon Musk (not a cabinet member but highly influential), strictly speaking, is not a cabinet member, but his influence is enormous.
In the past: he criticized Trump multiple times, opposed his climate policies and rhetoric, and supported other candidates. Later: he gradually moved closer on issues like free speech, regulation, and industrial policy, becoming an important external ally of Trump's camp.