Senators John McCain (R-AZ) and Jon Kyl (R-AZ) have defended their state's controversial new immigration crackdown on grounds of spiraling crime in Arizona due to the lack of security along the US-Mexico border. But new studies finds that spillover violence from Mexico has been "declining," bringing into question the timing and validity of this rationale.

Raw Story reported Tuesday on a new analysis by ABC News which finds that violence and crime on the US-Mexico border -- while amplified in perception due to a few recent widely-documented incidents -- has been "on the decline" in recent years.

In Arizona, property and violent crimes rates have fallen from 512 per 100,000 people in 2005 to 447 per 100,000 people in 2008 (beyond which no data is presently available), according to statistics from the US Bureau of Justice Statistics compiled by the research group Immigration Policy Center.

You might get a different impression listening to McCain, who chalked up the law enacted last month to "unending and constant flow of drug smugglers and human traffickers" -- or Kyl, who claimed it was a response to a "thriving environment for human trafficking."

"Kyl and McCain are hyping the story about the crime and mayhem because it panders to the right and it throws sand in the face of skeptics and critics," said Frank Sharry, executive director of the pro-immigration reform group America's Voice, in a statement to Raw Story.

"They use the hype to justify their embrace of a state law that mandates ethnic discrimination. They use the hype to blame [Homeland Security Secretary Janet] Napolitano and [President Barack] Obama for ignoring the problem," he added.

Critics charge that the law -- which Arizona Gov. Jan Brewer alleged was catalyzed by cross-border "murder, terror and mayhem" and "uncontrolled" violence -- will lead to racial profiling against minorities, particularly Hispanics, by mandating police to probe immigration status during lawful encounters if there is "reasonable suspicion" the subject is undocumented.

McCain and Kyl voted for the last major immigration overhaul effort in 2007, which included a pathway to citizenship for unauthorized immigrants -- McCain was a lead sponsor of the bill. Both have, along with the rest of their party, declined to support similar legislation this year.

"They use it to justify their refusal to work with Democrats and the White House on comprehensive immigration reform -- the approach they both championed in the past as the only way to truly secure the border," Sharry said.

The Arizona measure, which most Americans favor according recent polls by Gallup and CBS/New York Times, has galvanized activists on both sides of the divisive issue. While President Obama and Democratic leaders have emphasized their support for a comprehensive overhaul, all indications are that it will not pass during the remainder of this Congress.