“What’s the Matter with Kansas?” The 2004 bestseller by liberal commentator Thomas Frank chronicled the rise of populist conservatism in his home state – and by extension, the United States. Now abortion-rights opponents must be asking themselves the same question: How could conservative Kansas have voted Tuesday to keep the state’s constitutional right to abortion?

It wasn’t even close. Some 59% of Kansans voted against an amendment that would have allowed the state’s supermajority Republican legislature to tighten restrictions or ban abortion outright. Legislators had scheduled the referendum for primary day, with typically low turnout that gives the most motivated voters outsize influence.

Turns out it was abortion-rights supporters – mostly Democrats and unaffiliated voters, and yes, many Republicans – who were more motivated, defying polls that had pointed to a close result. MSNBC’s Steve Kornacki suggests “at least 20% of R’s were No’s.”

In this first test of voter sentiment since the Supreme Court overturned the nationwide right to abortion, there are lessons for everyone.

Foremost, Kansas reminds us that voters do not necessarily embrace their party’s entire platform. Some Republicans lean libertarian on social issues – that is, they don’t want the government telling people what to do on personal matters. They may oppose abortion for themselves or loved ones, but aren’t comfortable with tough restrictions or bans.

Second, Kansas showed the power of organizing. The high court’s June 24 ruling overturning Roe v. Wade was “a wakeup call for a lot of moderate Kansans who weren’t engaged on this issue because they thought there was federal protection for abortion care,” Ashley All of Kansans for Constitutional Freedom, the main organization opposing the amendment, told FiveThirtyEight.

After June 24, more than 500 people a week volunteered to do voter outreach, up from 44 volunteers a week, Ms. All added. With nearby states severely restricting or banning abortion, Kansas has become a regional hub for the procedure.

Kansans who support abortion rights are angry – rocket fuel for voter mobilization. “Anger is the best motivator for turnout,” says Democratic pollster Celinda Lake.

But Tuesday’s vote does not necessarily foretell Democratic success in November. The economy remains issue No. 1 for most, though views on abortion could swing close races.

Anti-abortion forces are undaunted. Value Them Both, a pro-amendment group, tweeted last night: “This outcome is a temporary setback, and our dedicated fight to value women and babies is far from over.”