The 2028 presidential election may seem far away, but in political terms, it’s already approaching. Serious contenders will spend the next few months building donor networks, testing messages, and positioning themselves for formal campaign announcements, which traditionally begin after the midterms. While other names may emerge, the Republican conversation currently centers on two figures: Vice President JD Vance and Secretary of State Marco Rubio.

Both men will enter the race carrying the accomplishments of the Trump administration. But they will also inherit its controversies. That creates what may become the defining question of the election:

What would you have done differently from President Donald Trump?

It is an unavoidable question for anyone running to succeed a president from their own party. Candidates must convince voters they will continue a successful agenda while also demonstrating independent judgment. Simply pledging to repeat everything their predecessor did rarely satisfies primary voters — or the broader electorate.

Democrats learned this lesson the hard way. During the 2024 campaign, then-Vice President Kamala Harris faced repeated questions about what she would have done differently from President Joe Biden. Her reluctance to identify meaningful differences became one of the defining criticisms of her campaign, reinforcing the perception that she represented continuity rather than change.

Republicans in 2028 will likely face the same test.

At this stage, no issue appears more likely to define that conversation than the administration’s handling of Iran. Whether voters ultimately judge the war as a success or failure will depend on developments over the next two years. If the conflict ends with an “agreement” that advances American interests, it could become a political asset. If it remains unresolved or is widely viewed as falling short of its objectives, Republican candidates will inevitably be asked what they would have done differently.

That is where Vance and Rubio could face very different political calculations.

Rubio has been closely associated with the administration’s foreign policy and public defense of its decisions. That could make it more difficult for him to argue that he would have pursued a significantly different approach without appearing to distance himself from policies he helped implement.

Vance, by contrast, has spent much of his vice presidency emphasizing a different role. In public interviews, including a lengthy conversation with Joe Rogan, he argued that the vice president’s responsibility is to faithfully execute the president’s agenda rather than substitute his own preferences. At the same time, he has continued to describe himself as skeptical of prolonged foreign military interventions while insisting that, once the president makes a decision, his responsibility is to help make that policy succeed.

Politically, that distinction could prove significant.

If voters conclude that the administration’s Iran policy ultimately succeeded, both candidates can argue they helped deliver an important foreign policy achievement. But if many voters instead believe mistakes were made, Vance may have greater flexibility to explain how he balanced internal debate with loyalty to the administration’s final decisions. Rubio, because of his more visible role in shaping and defending foreign policy, may find it harder to create that distance.

None of this guarantees either candidate an advantage. Presidential campaigns are shaped by economic conditions, international events, personalities, and unforeseen crises. New candidates could also reshape the race entirely before a single vote is cast.

But every election eventually turns on one defining question that candidates cannot avoid.

For Republicans in 2028, that question may not only be whether they supported President Trump, but if they can credibly explain where they would have led differently — and whether voters believe the answer.

Both Vance and Rubio are among the greatest political talents the Republican Party has produced in decades, and I would enthusiastically support either as president. Both deserve the opportunity to run, whether in 2028 or in the election that follows. The strongest possible outcome may be for them to share the same ticket, giving Republicans one of their most formidable presidential teams in the last century.

Still, admiration for both men cannot obscure the political reality. Voters do not reward candidates who refuse to acknowledge mistakes or explain how they would improve upon the status quo — unless that status quo has delivered undeniable success. The country is far better off than it was in 2024, but if current controversies remain unresolved, the Republican nominee will have to confront them directly. Loyalty to the Trump administration will not be enough. The candidate who offers the most credible explanation of what should continue and what must change will have the clearest path to the presidency.