Democrats passed their landmark legislation in time for the midterms. Now they need to sell it to voters — and the first phase of that effort is taking shape.

In plans shared first with POLITICO, a trio of Democratic groups — Climate Power, the League of Conservation Voters and Future Forward USA Action, a nonprofit backed by several major Democratic donors — is dropping $10 million on a national TV ad campaign to define the legislation in the minds of voters. It’s the largest paid ad effort to bolster the legislation so far, as an array of Democratic groups and candidates kick off a 90-day sprint to promote the package and defy a brutal electoral environment for the party.

“The magnitude, the scope and the importance of what Congress and Biden just did for climate change is transformational … and it is essential that people understand the magnitude of what just happened,” said Pete Maysmith, senior vice president of campaigns at the League of Conservation Voters. He predicted that Republicans would try to mislead voters about the bill, and “we can’t sit around and wait for that to happen. We need to aggressively tell this story.”

It’s a task the party has been particularly bad at in the past — most notably in 2010 after the passage of Obamacare — and there’s no guarantee this time will be different.