Conservative legal activist Leonard Leo’s dark money network has spent $18 million trying to block a ballot measure to enshrine abortion rights in Ohio’s constitution — accounting for nearly 60 percent of what abortion opponents have reported raising in advance of the November 7 election, according to new state campaign finance data.

As President Donald Trump’s judicial adviser, Leo built the conservative Supreme Court supermajority that overturned federal protections for abortion rights last year, allowing states to ban the procedure. Now, we’re seeing how much Leo — the beneficiary of a historic $1.6 billion dark money donation — will spend in order to restrict abortion access at the state level.

“Leonard Leo has spent his entire career working to end abortion access at all levels of government, stripping millions of women of their critical rights and freedoms,” said Caroline Ciccone, president of the liberal watchdog group Accountable.US. “Leo leveraging his billion-dollar network to meddle in this election has dangerous, life-altering repercussions for Ohioans and Americans everywhere.”

Ohio has been at the center of America’s abortion debate since the Supreme Court’s decision overturning Roe v. Wade, which allowed states to move forward with bans on the procedure.

The decision allowed Ohio Republicans to temporarily enforce a highly restrictive law banning abortions after six weeks, with no exceptions for victims of rape or incest and led to a national controversy about an Ohio child who was forced to travel to Indiana for an abortion after being raped.

The six-week abortion ban was recently blocked by a state judge, so abortion is currently legal in the state up until twenty-two weeks. However, Republicans are pushing the state’s conservative Supreme Court to overturn this injunction.

Issue 1, on the ballot next month, could render that court fight moot — and establish an individual “right to make and carry out one’s own reproductive decisions” in Ohio’s state constitution.

So far, polling indicates that voters are likely to approve the measure — a prospect made easier after Ohio voters rejected an effort by abortion opponents to raise the threshold required to pass ballot amendments.

Leo’s network, however, is pulling out all the stops to defeat the measure.

State records show that Leo’s Concord Fund has donated $18 million to a committee called Protect Women Ohio Action, including more than $6 million in the past two months. The committee disclosed paying $71,000 earlier this month to CRC Advisors, a consulting firm chaired by Leo, for polling and research.

Protect Women Ohio Action has reported donating about $17 million to the main committee opposing Issue 1, called Protect Women Ohio. Together, the two similarly-named groups have raised about $31 million to oppose the abortion ballot measure.

Donations from Leo’s network account for nearly 60 percent of what the groups have raised.

Amy Natoce, press secretary for Protect Women Ohio, pointed out in an email that committees supporting the abortion ballot measure have received millions in “out-of-state dark money funding” — including from Democratic megadonor George Soros’s Open Society Policy Center, the abortion rights group Planned Parenthood Action Fund, and the liberal dark money hub Sixteen Thirty Fund.

Gary Marx, the Concord Fund’s president, told the Lever in a statement: “Our support for Protect Women Ohio pales in comparison to the $25 million the Arabella Advisors network and their allies have poured into Ohio to support Issue 1, which undermines parental rights and removes reasonable regulations on late-term abortions, including protections for babies that can feel pain.” (Arabella Advisors administers the Sixteen Thirty Fund.)

Protect Women Ohio has swarmed voters with TV and digital ads — including ads that misleadingly suggest that Issue 1 would allow abortions at any time during pregnancy.

One ad features a personal appeal from Ohio governor Mike DeWine (R) and his wife, Fran.

“Issue 1 would allow an abortion at any time during pregnancy, and it would deny parents the right to be involved when their daughter is making the most important decision of her life,” Fran DeWine claims in the ad.

Mike DeWine adds: “I know Ohioans are divided on the issue of abortion. But whether you’re pro-life or pro-choice, Issue 1 is just not right for Ohio.”

Another ad from Protect Women Ohio calls on voters to “stand with Trump against late-term abortions.”

Issue 1’s text says that “abortion may be prohibited after fetal viability,” while clarifying that “in no case may such an abortion be prohibited if in the professional judgment of the pregnant patient’s treating physician it is necessary to protect the pregnant patient’s life or health.”