Less than a week after the Islamic State’s attack on Paris and the discovery that one of the attackers carried a fake Syrian passport during the incident, more than half of the nation’s governors have announced that their states won’t accept any Syrian refugees.

President Obama had announced in September, as the conflict in Syria worsened and the volume of refugee families rose dramatically, that the United States would accept 10,000 of those refugees. They, like the approximately 70,000 other refugees the United States already planned to take in this year, undergo a lengthy screening process designed to check for terrorism and national security risks before they are offered admission. Once here, federal agencies with the help of regional nonprofit organizations will have to integrate these future Americans into one of several dozen local communities across the United States.

But now the announcements by state and local officials raise two related questions: (1) can states limit the federal government’s resettlement of refugees, and (2) what are the likely political causes and effects of these refusals? Quite clearly, the answer to the first question is no. Despite the governors’ forceful rhetoric, states cannot reject Obama’s refugee policies. What they can do, however, is complicate the process of placing and integrating Syrians.

The governors’ reactions are indicative of a larger, post-9/11 trend of states attempting to play a greater role in regulating immigration. As we chronicle in our book, this state-level involvement over the past several years has been heavily partisan, mirroring the dynamics evident at the national level. The governors’ opposition to Syrian refugees fits this pattern. Most of the pushback has come from Republican governors, who have seized upon refugee admissions as part of a portfolio of policies focused on deterring immigration and heightening enforcement. It is not a coincidence that the overwhelming majority of governors who have taken an anti-Syrian refugee stance are from states that are also challenging Obama’s deferred action program from November 2014, and were also sites of prominent state immigration enforcement and employment restriction laws prior to 2012.

No matter what these governors say as part of their political grandstanding, states cannot actually stop Syrian refugees from settling within their borders. The lion’s share of refugee placement is shouldered by a network of nongovernmental organizations that partner with the State Department to help refugees find places to live and work and ease their transition into new communities. Yes, federal law contemplates a role for states and state agencies in the refugee resettlement process, but that role is limited to advice-giving and consultation. State and local officials may offer input to the State Department and provide recommendations about areas of resettlement. In addition, states can tap into federal funds to create state agencies that would augment the work of the State Department and the nongovernmental organizations.

Federal law emphatically does not provide authority for states to nullify the president’s decision to increase the number or type of refugees or where those refugees will eventually live, though. Congress, in the Refugee Act, lodged sole power over those decisions with the president and the State Department, an important recognition of the connection between our country’s refugee policy and foreign policy. Both the Constitution and federal law prohibit states from picking and choosing among refugees, as they are proposing to do here by discriminating against Syrians. Indeed, multiple Supreme Court decisions dating back to the late 1800s make it clear that states are constitutionally prohibited from discriminating on the basis of national origin or denying the opportunity to live or seek work to immigrants once the federal government has seen fit to admit them.

If these states maintain their opposition despite the law’s clarity, it is highly likely that the federal government could seek a court order overriding the governors. But the politics are more intricate than the law.

By loudly and ostentatiously announcing their intentions, these governors have raised the stakes of any decision by the federal government. Sending refugees to states where governors have signaled opposition might entail a more difficult integration process for refugees. For example, if some states disband or defund their refugee resettlement agencies in protest against Obama’s plan, the prospect of future refugee resettlement, from any country, would become more difficult. The mayor of Roanoke adopted this strategy, directing all local agencies stop providing aid to Syrian refugees. Even more troubling, he chose to invoke our nation’s deplorable internment of Japanese Americans during World War II to support his rejection of Syrians. These highly publicized statements signal to the putative refugees that certain places will be less than friendly for making their new lives, and portend a general atmosphere of suspicion and social exclusion.

The federal government could seek to avoid this confrontation, as at least six state governors — all Democrats —have affirmed their willingness to house refugees in their states. Putting refugees only in those states would certainly avoid conflict. On the other hand, that creates logistical difficulties and costs, and sets a dangerous precedent, by conceding the power of reluctant states to alter refugee policy. These dynamics were vividly on display recently, when the refugee resettlement organization in Indiana decided on short notice to redirect a Syrian family to Connecticut. While officers from the organization attempted to clarify that this move should not be understood as a precedent for future resettlement, it is impossible to see this as anything but an example of our national refugee policy being dictated by the whims of a state governor.

Even if the governors’ revolt is ultimately unsuccessful in blocking the resettlement of Syrian refugees, it has placed the refugee screening process under intense public scrutiny and forced the administration into either directly confronting state officials or modifying its plans to avoid a conflict. Indeed, emboldened by this state-led opposition, GOP lawmakers in Congress are now threatening a government shutdown unless the administration reconsiders its Syrian refugee policy.

Admissions decisions and refugee selection are highly sensitive choices rightly left to the federal government’s control, with significant discretion for the president’s ability to respond to international crises. But while these governors have little legal ground to stand on, their statements nevertheless showcase the practical and symbolic importance of states even in matters traditionally understood to be beyond their purview. These recent statements contribute to a larger shift in our political and legal landscape, with states and localities serving as the battlegrounds for a nationwide, partisan contest over immigration policy. Obama should stand on his considerable legal authority and beat back this politicized challenge — to prevent Syrian refugees from becoming casualties not just of sectarian violence overseas, but also of this brewing federalism battle at home.