Hawaii Sen. Daniel Akaka says the American Bar Association has sent a letter to every U.S. senator urging support of the Native Hawaiian Government Reorganization Act.

The Hawaii Democrat said Friday that the letter sent this week outlines the bill’s constitutionality and its precedent within U.S. law.

He said it also details benefits of the U.S. providing parity to Native Hawaiians as indigenous people.

Akaka, the bill’s sponsor, said the letter helps address mischaracterizations and brings attention to the importance of the bill.

Akaka said he remains optimistic the Senate will be able to consider the bill this year.

Hawaiians are the last indigenous people in the U.S. who haven’t been granted federal recognition.