Washington (CNN) Planned Parenthood's political arm is targeting eight states with competitive Senate and governor's races in its largest-ever midterm election campaign.

The offensive is set to cost $20 million, an initial mark that the organization's officials say is all but certain to be exceeded.

The investment from Planned Parenthood Action Fund and Planned Parenthood Votes, the organization's political entities, makes it one of the biggest outside spending forces in Democratic politics headed into a cycle in which the party sees a rare opportunity to pick off GOP seats across the map.

It's part of Planned Parenthood's effort to sustain the momentum of the Women's March the day after President Donald Trump's inauguration and turn women's health care and reproductive rights into issues that drive voters to the ballot box to oppose Trump and GOP candidates.

The initial list of targets includes eight states: Arizona, Florida, Michigan, Minnesota, Nevada, Ohio, Pennsylvania and Wisconsin.

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