The Supreme Court said Tuesday it was declining, for now, to hear challenges against an Illinois ban on assault weapons — cases that have quickly turned into a major test of the legality of the popular AR-15 rifle.

Justice Clarence Thomas indicated that his colleagues thought the cases weren’t yet ripe for the high court and needed more development before lower judges.

But he said the issue will have to be dealt with as the justices continue to figure out the extent of the Second Amendment and to what, whom, where and when it applies.

“We have never squarely addressed what types of weapons are ‘Arms’ protected by the Second Amendment,” Justice Thomas wrote in a statement about the refusal.

Justice Samuel A. Alito Jr. said he would have taken the cases right now.

Justice Thomas said it’s particularly important that the justices decide whether AR-15-style rifles are protected.

The 7th U.S. Circuit Court of Appeals, which has allowed Illinois’ ban to go into effect while the challenges are being argued, has ruled that AR-15s are “militaristic” and so are beyond protection of the Second Amendment.

Judge Diane Wood said she sees the AR-15, a semiautomatic weapon, as nearly equivalent to automatic rifles carried by the U.S. military.

“Indeed, the AR-15 is almost the same gun as the M16 machinegun. The only meaningful distinction, as we already have noted, is that the AR-15 has only semiautomatic capability (unless the user takes advantage of some simple modifications that essentially make it fully automatic), while the M16 operates both ways,” Judge Wood wrote.

Justice Thomas called her ruling “contrived” and “contorting.”

“It is difficult to see how the Seventh Circuit could have concluded that the most widely owned semiautomatic rifles are not ‘Arms’ protected by the Second Amendment,” he wrote.

• Stephen Dinan can be reached at sdinan@washingtontimes.com.