Voter registration in Colorado surged, particularly among women, in spikes that coincide with the U.S. Supreme Court’s decision overturning Roe v. Wade, a Colorado Politics analysis shows.  

The analysis, which delved into voter registrations between May and September of this year, shows women, especially Democrats, are outpacing registrations by men in all but one of the seven most competitive Senate races. The surge was most pronounced in three congressional districts: CD2, which includes Boulder; CD5, which covers Colorado Springs; and, the battleground CD7, which includes Jefferson County and parts of Douglas County.

Confounding variables could explain the spikes, in part or in whole. But at the outset, the data seem to support the hypothesis the court decision is a motivating factor in election engagement. 

For example, between January and May of this year, new voter registrations for Democratic women averaged just under 2,900 per month. In June, the month when the Dobbs decision was published, the number jumped to 5,737, almost double the average.

New voter registrations for Republican women averaged 1,350 per month between January and May, but 3,079 Republican women registered in June, more than double the monthly average.

Unaffiliated women put in about 8,000 new voter registrations per month between January and May, but in June that jumped to 11,486, an increase of more than 40%. 

This surge stands in sharp contrast to voter registration trends in Colorado in 2014, when voter registrations by women declined between Jan. 1 and Sept. 1, 2014. In 2018, voter registrations by women increased only slightly in the same time period.

Ryan Winger of Magellan Strategies told Colorado Politics he found “non-polling” data useful in seeing trends. 

Winger doesn’t regard the spikes as a “game changer in CO but a trend nonetheless.” Crucially, he said, the analysis reflects behavior “without voters having the ability to hide by not responding to surveys.” Winger is referring to the difficulty pollsters face in getting people to participate in polls.

He added the Supreme Court’s ruling “probably was just a steroid shot into a trend that had already been occurring where women were more likely to register as U or D than R,” referring to unaffiliated voters, Democrats and Republicans, respectively.  

The data shows greater levels of new registrations after the leak and again after the ruling in Dobbs v. Jackson Women’s Health, in which the justices overturned the longstanding precedent guaranteeing access to abortion, leaving it to the states to decide the parameters of their abortion statutes. 

Politico reported on a leaked a draft of the Dobbs decision on May 2. The court’s published decision came out on June 24.

By that date, voter registrations in Colorado were already beginning to surge among women of all political persuasions, but most notably among unaffiliated and Democratic voters.

The New York Times observed a similar trend in at least five states – Florida, Idaho, North Carolina, Ohio and Pennsylvania – three of which are battleground U.S. Senate races. Notably, the Times said a week after the court’s decision, more than 70% of newly-registered voters in Kansas were women.

In August, Kansas voters voted down an amendment that would have stripped residents of the right to an abortion. The vote, at 59% against 41%, mirrored the most recent vote in Colorado Proposition 115, which would have banned abortions after 22 weeks gestation. The measure lost by a nearly identical 59% to 41% margin in 2020.

While the surge was most  in CD2, CD5, and CD7, voter registration changes appears to be considerably diminished in Congressional District 8, one of the most-watched races in the country. 

Some reports point out that Republicans had been registering to vote in greater numbers in the two years prior to the Dobbs decision, so Democrats in some states are only catching up.

That hasn’t been the case in Colorado, where Democrats held a steady lead in voter registrations over Republicans for the last six years. That said, the biggest jump in voter registrations have occurred among unaffiliated voters, although election results in the past two elections indicated they lean Democrat. Active women voters also outnumber men by about 70,000, according to the most recent statistics from the Secretary of State’s office.

The surge in Colorado could play a role in the state’s most hotly contested state Senate races.