An appeal filed in the U.S. Supreme Court on behalf of a group challenging the state’s 2012 reapportionment and redistricting plan as unconstitutional could be decided by the end of the year, an attorney for the plaintiffs says.

An appointed three-judge court of the 9th U.S. Circuit Court of Appeals last month denied the challenge from the group of eight voters who contend the plan violates the equal protection clause of the U.S. Constitution because it excludes 108,000 so-called "nonpermanent" residents from the population base used to allocate legislative seats among islands and determine boundaries for voter districts.

Robert Thomas, an attorney for the group, said under federal procedure for reapportionment cases, the appeal, which was filed Friday, bypasses the full 9th Circuit and goes straight to the high court, which must hear the case.

Attorneys now have 60 days to file "statements of jurisdiction" — legal briefs arguing their position to the court.

"In reapportionment cases, Congress requires the Supreme Court to consider the case," Thomas said Wednesday. "Now, they may just consider the case on the briefs, they may not actually have a hearing, but we’re hoping the Supreme Court has a hearing, has arguments.

"This is something that we anticipated all along. We still feel confident the Supreme Court will see the law the way we think it is and should be."

Plaintiffs are seeking to have the 2012 redistricting maps redrawn to include changes that would occur by including the nonpermanent residents in the population count. Excluding those residents, as the state Reapportionment Commission had to do because of a state Supreme Court ruling, shifted a state Senate seat to Hawaii island from Oahu.

Nonresident military members and their dependents, along with students who pay nonresident tuition, were among those left out.

The state attorney general’s office had argued that federal case law allowed the state to exclude certain residents from the population base to prevent distortions that might occur if large numbers of temporary residents were counted. State attorneys also argued the election planning process was too far along to start over and that having to draw new district maps could have caused extensive delays and jeopardized the Aug. 11 primary and potentially the Nov. 6 general election.

Thomas argued that excluding nonpermanent residents violated the equal protection clause of the U.S. Constitution. The lawsuit also contends the commission created districts of unequal size, leading to disproportionate representation in the state Legislature.

Reapportionment occurs every 10 years to redraw voter district boundaries to reflect changes in the population recorded in the most recent U.S. census.