Tom Steyer, the former hedge fund manager now spending millions of his personal fortune on a push to impeach the president, announced a new $10 million drive aimed at turning out Democratic voters in the midterms.

Delivering what his "Need To Impeach" operation billed as a major announcement from Michigan on Monday, Steyer said the new infusion of money would go toward television and digital ads, and on-the-ground organizing of the thousands of activists who have signed on to his impeachment petition.

"The people we elect in November will enter office knowing that they won in part because the American people want this president held to account and they want a Congress that will stop posturing and will start to address our real problems," he said during the announcement.

Some prominent Democrats have questioned whether elevating the impeachment issue would only serve to galvanize dispirited Republican voters to turn out this fall. But the potential 2020 Democratic presidential candidate, who will appear in Iowa on Tuesday, appeared to be setting himself up to claim a share credit if the party succeeds in winning back the House this fall.

He said his grassroots campaign has already delivered results for the party, citing the election of Conor Lamb in Pennsylvania's GOP-leaning 18th district last March. He said four of five voters in the district who had signed his impeachment petition turned out in the election, double the rate of all Democrats. Steyer's Need To Impeach says it has 5.5 million members.