The Court’s opinion in this case, Arizona v. Inter Tribal Council of Arizona, also establishes an important doctrinal rule regarding the power of Congress to push back against state election laws. The Constitution permits duly enacted federal laws to trump state law, a process known as “preemption.” Normally, however, courts should apply a presumption against preemption and assume that Congress did not intend to invalidate state law if the matter is uncertain. Scalia’s opinion holds that this presumption does not apply with respect to federal laws regulating federal elections, a holding which suggests Congress’ power to sweep away state election laws is quite sweeping.
As the Court points out, this broad view of the federal role in governing elections is consistent with the Constitution’s text, which provides that “[t]he times, places and manner of holding elections for Senators and Representatives, shall be prescribed in each state by the legislature thereof; but the Congress may at any time by law make or alter such regulations.” So a future Congress more supportive of voting rights has the power to sweep away voter ID laws and other methods of voter suppression that have recently popped up mostly in conservative states. By contrast, a future Congress more keen to voter suppression may have significant authority to impose its will on the nation, although this power would be checked by constitutional safeguards against many forms of voter suppression.
Scalia’s opinion is not, however, a total victory over Arizona’s attempt to make voter registration more difficult. Rather, the final section of his opinion suggests that Arizona could renew a request to the U.S. Election Assistance Commission to incorporate the state’s proof-of-citizenship requirement into the voter registration form, and that they could challenge any denial of this request in court. For the meantime, however, Arizona’s requirement is invalid.