COLUMBUS, OH - JUNE 21: Presumptive Democratic presidential nominee Hillary Clinton speaks to supporters on June 21, 2016 at the Construction Arts & Auto Technology building, Fort Hayes Metropolitan Education Center, in Columbus, Ohio. Clinton discussed her vision for a stronger America and her commitment to build an economy that she says will work for everyone. (Photo by J.D. Pooley/Getty Images)

COLUMBUS, OH - JUNE 21: Presumptive Democratic presidential nominee Hillary Clinton reaches for a phone while shaking hands with supporters on June 21, 2016 at the Construction Arts & Auto Technology building, Fort Hayes Metropolitan Education Center, in Columbus, Ohio. Clinton discussed her vision for a stronger America and her commitment to build an economy that she says will work for everyone. (Photo by J.D. Pooley/Getty Images)

COLUMBUS, OH - JUNE 21: Presumptive Democratic presidential nominee Hillary Clinton talks with supporters on June 21, 2016 at the Construction Arts & Auto Technology building, Fort Hayes Metropolitan Education Center, in Columbus, Ohio. Clinton discussed her vision for a stronger America and her commitment to build an economy that she says will work for everyone. (Photo by J.D. Pooley/Getty Images)

COLUMBUS, OH - JUNE 21: Presumptive Democratic presidential nominee Hillary Clinton waves to supporters on June 21, 2016 at the Construction Arts & Auto Technology building, Fort Hayes Metropolitan Education Center, in Columbus, Ohio. Clinton discussed her vision for a stronger America and her commitment to build an economy that she says will work for everyone. (Photo by J.D. Pooley/Getty Images)

(FILES) This file photo taken on March 17, 2011 shows an aerial view of the Diablo Canyon Nuclear Power Plant which sits on the edge of the Pacific Ocean at Avila Beach in San Luis Obispo County, California. Under a proposal announced on June 21, 2016 by Pacific Gas and Electric, the Diablo Canyon Power Plant, the states last operating nuclear facility, would be shuttered by PG&E after its current Nuclear Regulatory Commission operating licenses expire in November 2024 and August 2025. The power produced by Diablo Canyons two nuclear reactors would be replaced with investment in a greenhouse-gas-free portfolio of energy efficiency, renewables and energy storage, PG&E said in a statement. The power output loss would be compensated by using technologies that do not emit greenhouse gases, including renewable energy. / AFP PHOTO / MARK RALSTONMARK RALSTON/AFP/Getty Images

BERLIN, GERMANY - JUNE 21: German Chancellor Angela Merkel stands with children on a laboratory station during her visit to the Weydemeyerstrasse Kindergarten on Jne 21, 2016 in Berlin, Germany. Merkel visited the kindergarten as part of the "Day of Little Researchers", which is meant to promote enthusiasm for science among children. (Photo by Carsten Koall/Getty Images)

BERLIN, GERMANY - JUNE 21: German Chancellor Angela Merkel stands with children on a laboratory station during her visit to the Weydemeyerstrasse Kindergarten on Jne 21, 2016 in Berlin, Germany. Merkel visited the kindergarten as part of the "Day of Little Researchers", which is meant to promote enthusiasm for science among children. (Photo by Carsten Koall/Getty Images)

BERLIN, GERMANY - JUNE 21: German Chancellor Angela Merkel stands with children on a laboratory station during her visit to the Weydemeyerstrasse Kindergarten on Jne 21, 2016 in Berlin, Germany. Merkel visited the kindergarten as part of the "Day of Little Researchers", which is meant to promote enthusiasm for science among children. (Photo by Carsten Koall/Getty Images)