Final answer:
Texas has been most effective at winning cases related to immigration policy, leveraging competitive federalism to address their concerns over federal enforcement of immigration laws and the management of state implications of undocumented immigration.
Step-by-step explanation:
When exploring the concept of modern American Federalism, Texas has been involved in numerous court cases against the Federal government. Considering the precedents and the contentious nature of immigration federalism, Texas has historically been most effective at winning cases related to immigration policy.
Cases such as Arizona v. United States have demonstrated that while federal law supersedes state law in immigration matters, states like Texas continue to litigate in this area due to a perceived lack of federal enforcement and the desire to manage the implications of undocumented immigration within their borders.
Environmental litigation and regulatory disputes are also areas where states like Texas participate actively. However, given the expressed power of the Federal government over immigration as stated in the Constitution coupled with recent high-profile cases like U.S. v. Texas, Texas has been more effective in the immigration domain, often leveraging competitive federalism to advocate for their interests in this contentious policy area.