Story highlights FIRST ON CNN: Feds determine they don't have authority to assign poll observers

Last year, the Supreme Court struck down a section of the Voting Rights Act

Because of that ruling, the Justice Dept. has suspended posting observers in polls

There are exceptions to that change, in seven states covered by separate court orders

For the first time in decades, voters in Georgia are going to the polls Tuesday without the chance of having Justice Department observers inside their polling places.

CNN has learned that's because Justice Department lawyers in recent months have determined they no longer have legal authority to unilaterally assign poll observers after the Supreme Court ruling invalidating key sections of the Voting Rights Act

The department has suspended posting observers inside polling stations except for in nine jurisdictions in seven states covered by separate court orders, government officials said. The internal legal finding hadn't been made public before.

Observers had the authority to be inside polling places, and the department may still send monitors who keep an eye outside polling precincts. A spokeswoman for the Justice Department's civil rights division declined to comment.

The department has been sending election-day poll observers and monitors to some Georgia counties since at least 1966, a year after the landmark civil rights law authorized it. The observers were there to document any interference or intimidation against voters, usually racial minorities in areas with a history of discrimination.

At last count, the Justice Department said it sent personnel to observe and monitor elections in 153 counties and parishes in 11 states.

Proponents of the poll watching say it helps prevent irregularities and has been useful to ensure federal voting rights are protected for minorities.

The department didn't send anyone to monitor last month's Mississippi primary, which has been much disputed by losing tea party-aligned candidate Chris McDaniel. Incumbent victor Sen. Thad Cochran drew black Democratic Party voters to help defeat McDaniel in the GOP primary. McDaniel has alleged voting irregularities , but Mississippi judges have rebuffed his claims.

Last year, the Supreme Court struck down Section 4 of the Voting Rights Act, under which the Justice Department compelled oversight of voting law changes in a patchwork of jurisdictions in states around the country.

U.S. Attorney General Eric Holder has criticized the ruling and has urged Congress to pass new legislation to restore the Justice Department's oversight powers.