Studying and forecasting the policy behavior of US President Donald Trump in his second term, “Trump 2.0,” is becoming one of the most significant theoretical challenges for political scientists. If the 2017–2020 term has weakened the traditional predictive power of the US presidential model, the 2025–2029 term shows an even greater degree of structural uncertainty. This is not only due to the personalization of Trump’s power, but also reflects the transformation of the internal political environment and the volatility of the international system. Fully recognizing these factors allows us to understand that the problem lies not only in the unpredictable personality of Trump but also in the fact that the US political system under a “Trump-style” president has become difficult to predict by conventional methods.
First of all, it must be noted that the US presidential model in most classical works almost all describe the institutional ecosystem as operating in the following way: The White House operates based on the mechanism of interagency consultation; the implementation agencies, such as the Department of Defense or the Department of State, have the role of stabilizing the policy process; and the president adjusts his behavior within the framework of meeting the expectations of the political party, Congress, and public opinion. Trump, especially in the current context, does not meet any of these assumptions. The increasing degree of personalization of power, the elimination of “buffers” that once constrained decisions (such as the traditional national security team), and the increased political focus on absolute loyalty make predictive models based on “executive practice” no longer analytically valid.
This is accompanied by a profound transformation of the legal environment. A president who is bound by civil or criminal lawsuits means that political action is influenced more by the logic of defense, the logic of voter mobilization, and the logic of controlling public opinion than by purely strategic criteria. This configuration makes policy behavior no longer consistent with a common strategic trajectory, but easily broken according to the rhythm of legal judgments.
One factor that significantly increases the uncertainty in the Trump 2.0 forecast is the restructuring of the personnel apparatus. Contrary to popular opinion, Trump’s first term still relied on many figures from the security world with pragmatic views, such as James Mattis, HR McMaster, John Kelly, and Rex Tillerson. These figures, with their political experience and understanding of the security structure, contributed to slowing down many of the president’s explosive decisions. However, the personnel picture for the 2025–2029 period is completely different, with the level of personnel selection based on loyalty and the emergence of stronger, more hawkish ideological advisory groups in an environment where expertise is no longer the central criterion.
It is impossible not to consider the volatility of the international system, a factor that Trump interacts directly with but which is decisive for his unpredictability. In the post-Cold War period, US presidents usually operated in a relatively stable environment in terms of global power structure; even the 9/11 event did not fundamentally upset the nature of the system when the US remained the dominant power pole, Western allies maintained strategic cohesion, and major rivals had relatively easy-to-model behavioral patterns. However, from 2022 onwards, US-China competition has entered a full-scale phase, the Russia-Ukraine war has been prolonged, and middle power blocs have emerged with a higher degree of autonomy. In such a fragmented and multi-layered environment, US presidents’ behavior will increasingly depend on real-time developments to respond. Thus, the same political figure may have a completely different policy response depending on the specific international “conflict” or “peace” at the time of the decision, which significantly reduces the ability to rely on precedent for forecasting.
Another aspect that forces political science analysis to adjust its methodology is the inherent contradiction in the Trump 2.0 agenda. Instead of a consistent direction, the policy program covers many overlapping areas such as trade, immigration, NATO issues, defense industry, border control, US-China relations… but lacks an integrated strategic framework as the main driving force. Each area operates at its own pace, under the direct impact of public opinion, political pressure from voter groups, and especially calculations of personal power. The absence of a “strategic core” makes it difficult for analysts to determine which priorities to infer the logic of Trump’s decision-making from.
Another key point is the gradual disintegration of the “soft constraints” in American politics. For decades, the White House operated not only by the Constitution but also by a network of norms. These are informal but crucial factors in maintaining policy stability and predictability. However, when a president can overturn or ignore unwritten norms from diplomatic rules to alliance approaches, these soft constraints no longer serve as constraints on behavior. As a result, researchers cannot use the “institutions of expectation” that are used to assess presidential behavior. Instead, analysis must rely more on the logic of personal power and exogenous motivations.
When all of these factors are combined, the uncertainty in the Trump 2.0 forecast is multi-layered. Uncertainty comes from the human factor of individualism, the ability to change quickly according to the context, and the tendency for confrontational politics. Uncertainty comes from the institutional structure of the declining role of the specialized apparatus, deep polarization in Congress, and the absence of stabilizing institutions. Uncertainty comes from the international environment, which is constantly moving and unpredictable. These three layers of uncertainty interact to form a nonlinear system, where small changes in one variable can lead to large changes in the trajectory of US policy.
So the right question is not “why is Trump unpredictable,” but “why has the political-institutional-international system under Trump become so volatile that it has rendered most traditional forecasting models ineffective.” This is a theoretical issue. Forecasting models of the US president have long relied on the assumption of structural stability, not just on individual behavior. When that assumption is shaken, analysis needs to shift from linear to multi-scenario models, combining quantitative assessment with qualitative analysis in real time and being ready to simulate unexpected events. This brings the study of Trump 2.0 closer to strategic risk analysis than traditional forecasting of foreign policy.
The study of Trump 2.0 therefore requires a new approach that does not seek a unified interpretation of “what Trump will do,” but constructs a spectrum of weighted scenarios in which the central variable is not just Trump, but the profoundly changed political and geopolitical structure around him. Only then can political science describe, let alone predict, a period that could be seen as a major test of traditional understandings of executive power in contemporary American politics.
