Reid's statement came in reaction to the court's ruling on SB 1070 on Monday. Provisions in the law that allowed the arrest of foreigners suspected of having committed a deportable offense, outlawed illegal immigrants from working in the United States, and also outlawed employers from hiring illegal immigrants were all struck down.

The court did, however, uphold a controversial provision in the law allowing law enforcement to check the immigration status of suspects who may have committed an unrelated crime.

Reid said the Obama administration was right to challenge the law.

"With three out of the four provisions being struck down, the ruling shows that the Obama administration was right to challenge this law, which was not just ill-advised but also unconstitutional," Reid said. "I am greatly concerned that the provision putting American citizens in danger of being detained by police unless they carry their immigration papers at all times will lead to a system of racial profiling. This is a strong reminder that ultimately, the responsibility for fixing our nation’s broken immigration system lies with Congress."

In the statement, Reid also praised a new immigration policy directive from President Obama that the United States would stop deporting illegal immigrants who came to the country illegally when they were young.

"President Obama’s decision to defer deportation of young people brought here through no fault of their own was necessary precisely because Republicans have so far refused to work with Democrats on forging common-sense solutions to our immigration challenge that are fair, tough and practical," Reid said.

Additionally, Reid criticized Mitt Romney for saying that the immigration law could be seen as a "model" for a national immigration policy.

"Looking ahead to the immigration debate, it is disturbing that Mitt Romney called the unconstitutional Arizona law a ‘model’ for immigration reform," Reid added. "Laws that legalize discrimination are not compatible with our nation’s ideals and traditions of equal rights, and the idea that such an unconstitutional law should serve as a ‘model’ for national reform is far outside the American mainstream."

Meanwhile, both Republican senators from Arizona, Sens. John McCainJohn Sidney McCainTrump knocks CNN for 'completely false' report Gaetz was denied meeting The Hill's Morning Report - Presented by Tax March - Biden, lawmakers start down a road with infrastructure Sylvester Stallone reportedly joins Trump's Mar-a-Lago MORE and Jon Kyl, released a statement said the Supreme Court's ruling validated the provision allowing local law enforcement to check suspects' immigration status.

"While we still want to fully review the Supreme Court’s decision, today’s ruling appears to validate a key component of Arizona’s immigration law, SB 1070," McCain and Kyl said in the joint statement. "The Arizona law was born out of the state’s frustration with the burdens that illegal immigration and continued drug smuggling impose on its schools, hospitals, criminal justice system and fragile desert environment, and an administration that chooses to set enforcement policies based on a political agenda, not the laws as written by Congress."