Since then-Delaware Senator Joe Biden first authored the law in 1994, the Violence Against Women Act (VAWA) has earned bipartisan praise for providing vital protections against domestic violence and assistance to victims. But of the eight Senators — all Republicans — who voted Monday against even considering VAWA renewal, at least four apparently did so because they believe the bill is unconstitutional.

Several of these senators have expressed similarly radical views about the constitutional role of the federal government in other contexts. Sen. Mike Lee’s (R-UT) claimed that national child labor laws, Social Security and Medicare violate the Tenth Amendment, for example; and Sen. Ted Cruz (R-TX) once led a Tenth Amendment project at a conservative think tank and co-authored a paper proposing an unconstitutional process to nullify the Affordable Care Act. The four senators who claim that the Violence Against Women Act is unconstitutional are:

1. Sen. Jim Risch (R-ID): In a statement, Risch explained: “It is at the state and local level where I believe enforcement and prosecution must remain. The federal government does not need to add another layer of bureaucracy to acts of violence that are being handled at the state and local level. In addition to my 10th Amendment concerns , this legislation raises additional constitutional questions regarding double jeopardy and due process. I opposed this legislation, however well intended it was, because it is another effort of the federal government extending its reach into the affairs of state and local jurisdictions.”

In a statement, Risch explained: “It is at the state and local level where I believe enforcement and prosecution must remain. , this legislation raises additional constitutional questions regarding double jeopardy and due process. I opposed this legislation, however well intended it was, because it is another effort of the federal government extending its reach into the affairs of state and local jurisdictions.” 2. Sen. Rand Paul (R-KY): In a 2012 letter explaining his opposition to last year’s VAWA re-authorization attempt, Paul wrote: “ Under our Constitution, states are given the responsibility for prosecution of those violent crimes. They don’t need Washington telling them how to provide services and prosecute criminals in these cases. Under the Constitution, states are responsible for enacting and enforcing criminal law. As written, S. 1925 muddles the lines between federal, state, local and tribal law enforcement.”

In a 2012 letter explaining his opposition to last year’s VAWA re-authorization attempt, Paul wrote: “ They don’t need Washington telling them how to provide services and prosecute criminals in these cases. Under the Constitution, states are responsible for enacting and enforcing criminal law. As written, S. 1925 muddles the lines between federal, state, local and tribal law enforcement.” 3. Sen. Mike Lee (R-UT): In 2012, Lee claimed VAWA “ oversteps the Constitution’s rightful limits on federal power. Violent crimes are regulated and enforced almost exclusively by state governments. In fact, domestic violence is one of the few activities that the Supreme Court of the United States has specifically said Congress may not regulate under the Commerce Clause. As a matter of constitutional policy, Congress should not seek to impose rules and standards as conditions for federal funding in areas where the federal government lacks constitutional authority to regulate directly.”

In 2012, Lee claimed VAWA “ Violent crimes are regulated and enforced almost exclusively by state governments. In fact, domestic violence is one of the few activities that the Supreme Court of the United States has specifically said Congress may not regulate under the Commerce Clause. As a matter of constitutional policy, Congress should not seek to impose rules and standards as conditions for federal funding in areas where the federal government lacks constitutional authority to regulate directly.” 4. Sen. Ted Cruz (R-TX): A Cruz spokeswoman told ThinkProgress: “For many years, Senator Cruz has worked in law enforcement, helping lead the fight to ensure that violent criminals — and especially sexual predators who target women and children — should face the very strictest punishment. However, stopping and punishing violent criminals is primarily a state responsibility, and the federal government does not need to be dictating state criminal law.” While the statement does not explicitly call VAWA unconstitutional, his previous comments leave little doubt that that is what he means.

These senators’ apparent belief that the federal government cannot constitutionally play a role in preventing violence against women is not even shared by most Republican members of Congress. 216 House Republicans agreed just last year that the Constitution does not prohibit a version of the Violence Against Women Act. The Supreme Court did strike down one piece of VAWA in 2000, but it left most of the law intact.

While the other four Senators who voted against the “motion to proceed” did not respond to a request for an explanation of their votes, Sen. Tim Scott (R) voted for the watered-down House version of VAWA last year and Sen. Marco Rubio (R-FL) claims he supports a scaled-back version of the legislation.