Over the weekend, former Vice President Al Gore waded into the most competitive Democratic Senate primary of the cycle.

Gore endorsed appointed Sen. Brian Schatz, who faces Rep. Colleen Hanabusa in what’s expected to be a close race next year in Hawaii. They’re both vying to fill the remaining two years of the late Sen. Daniel K. Inouye’s term.

“Thanks to Brian’s visionary leadership, Hawaii implemented its own groundbreaking Clean Energy Initiative,” Gore said in a statement. “As a result, Hawaii has tripled its renewable energy production from 6% to 18%. And we’re going to need Brian’s strong, outspoken leadership in Congress for many more years to get the job done.”