Donnelly announced Sunday he will support Judge Neil Gorsuch.
Donnelly becomes the third Democrat to back Judge Neil Gorsuch.
The Indiana Supreme Court has declined to take a case involving a man who was seriously injured in a crash and amassed over $625,000 in medical bills.
The ACLU says the ruling will impact what obstacles other states can enact when it comes to abortion access, including Indiana.
The Supreme Court's 4-3 ruling means the policies at many Indiana colleges will stand.
An Indiana couple wants the state supreme court to weigh in on whether newborn blood samples can be destroyed.
Attorney General Greg Zoeller joined more than 25 other states requesting an emergency stay on the Environmental Protection Agency's Clean Power Plan.
Indiana and the city of South Bend are wading into a redistricting case set for oral arguments at the US Supreme Court on Tuesday.
The decision could have a major impact on Indiana as lawmakers prepare to examine ways to take some of the politics out of electoral redistricting.
The majority opinion states the Environmental Protection Agency failed to account for the costs of implementation of its emission regulations.