WASHINGTON — With the Democratic primary all-but-officially over, the party’s biggest super PAC, Priorities USA, is preparing a nearly $65 million TV ad blitz for the fall campaign against President Donald Trump in six battleground states, the group told NBC News.

Likely Democratic nominee Joe Biden signaled to donors last week that he wants them to support the super PAC, which was initially founded by alumni of former President Barack Obama’s campaign to boost his 2012 re-election.

This year, the group plans to spend $200 million supporting Biden and attacking Trump, and says it has already been outspending Trump’s campaign on TV and digital platforms in key states since last summer.

The new $64.7 million in ad reservations through November include a heavy investment in Michigan ($17 million), Pennsylvania ($13 million), Florida ($13 million) and Wisconsin ($10.4 million), along with smaller but still sizable investments in Arizona ($6.5 million) and North Carolina ($4.8 million).

Notably not on the list is Ohio, the long-time swing state that has slipped further into the GOP column in recent years.

Priorities USA has previously announced $17 million worth of digital ads on platforms such as YouTube, Roku, and the music streaming site Pandora.

"The Trump campaign is sitting on hundreds of millions of dollars and his super PAC is already on air against Joe Biden. We won’t let our nominee face that alone," said Guy Cecil, the group's chairman. "Priorities has been outspending Trump in key battleground states for nine months, and by placing $65 million in TV reservations, we are committing to take the fight to Trump through Election Day."

Trump and his allies have had years to prepare for the general election while Democrats conducted their primary. Outside Democratic groups have tried to fill the void until Biden's campaign is fully up and running for fall after recharging its coffers.

Trump's campaign has protested a recent Priorities USA ad attacking his handling of the coronavirus crisis, saying it takes Trump's comments out of context and suing a small Wisconsin TV station to stop it from playing the ad. The group has vowed to fight Trump in court.

"Trump is doing everything he can to spread misinformation and block voters from hearing the truth, and we are committed to using every resource available to us to hold him accountable and elect Joe Biden the 46th President of the United States," Cecil added.

Campaigns are legally prohibited from coordinating strategy with super PACs, but lawyers in both parties have found ways to skirt that boundary, such as by having candidates appear at their fundraisers as long as they're careful not to explicitly ask for donations.

Another major pro-Biden super PAC, Unite the Country, was created to support him during the primary. But last week, Biden's campaign blessed the better-established Priorities USA, which spent about $200 million backing Hillary Clinton in 2016 and has about 100 people on staff.