Final answer:
The transformation toward a president-centered government evolved over time, but Franklin Roosevelt's administration with his New Deal policies is commonly recognized as a significant turning point.
Step-by-step explanation:
The turning point in American politics toward a president-centered government is widely considered to have happened during the administration of Franklin Roosevelt. President Roosevelt's New Deal policies and the centralization of power during his term in the wake of the Great Depression marked a significant shift in the role of the presidency in American government. However, earlier presidents such as Andrew Jackson also contributed to this trend. The election of 1828, which brought Andrew Jackson into office, signified the rise of the Democratic Party and showcased a movement toward a political authority that rested more with the majority. This shift continued to evolve with each subsequent administration, making it difficult to pinpoint a single definitive turning point.