Green New Deal co-author Ed Markey faces a Kennedy in today's Senate primary

It's primary day in Sen. Ed Markey's race against Rep. Joe Kennedy in Massachusetts.

Why it matters: Markey is among Capitol Hill's most prominent climate advocates. He co-authored the Green New Deal (GND) resolution, and a decade before that co-wrote the big climate bill that passed the House but went no further.

He's getting support from several climate groups and movement figures, including:

• Rep. Alexandria Ocasio-Cortez, who worked with Markey on the GND.
• The upstart Sunrise Movement, which helped push the GND into the political bloodstream and devoted lots of organizing resources to the race.
• Long-established green groups like the League of Conservation Voters Action Fund, the Sierra Club and the Environment America Action Fund.

Where it stands: Markey was considered the underdog heading into the race against a challenger from a family that's legendary in Bay State politics, but has held a lead in recent polling.

What they're saying: Veteran Massachusetts political consultant Mary Anne Marsh tells Politico that backing from AOC, Sunrise and Justice Democrats has changed the race.

• "That is what has allowed this remarkable makeover of Ed Markey to combat the fact he's 74 years old and been in Congress 44 years," Marsh said.
• "The way they did that was to make him the darling of the climate change warriors, and instrumental to that is ... Ocasio-Cortez."