How did Omaha become ground zero on abortion?

So, it appears that the Omaha mayoral race is reallyimportant to the Democrats, for some reason, but it has also turned into a giant cluster-fudge for them.

Monday last week, DNC chairman Tom Perez named Omaha in a list of races where the Democrat Party is investing in hopes of flipping the House in 2018. Thursday last, Bernie Sanders was seen in Omaha stumping for Democrat Heath Mello with a 45-min ramble about soaking the rich. But now Bernie and the DNC are under fire from their base because, it seems, Mello's progressive bona fides are insufficient.

Mello's crime? He's apparently not pro-abortion enough!Back in 2009, he co-sponsored a bill in the Nebraska Unicameral that would allow a woman seeking an abortion to see an ultrasound if she wanted to. See, freedom to choose doesn't include the choice to actually lay eyes on the "clump of cells" she's evicting from her body. We wouldn't want women to be informed or *gasp* make up their own minds about something as sacrosanct to progressives as abortion, would we?

This set off a debate among Democrats and progressives about whether there is even room for pro-life opinions in their tent. (spoiler: there isn't) Daily Kos, an early endorser, immediately withdrew their backing while also misstating the legislation they opposed. Outlets like WSJ and WaPo ran criticisms under the same erroneous characterization. NARAL labeled Mello’s candidacy “troubling” and a “betrayal. Perez issued a statement saying he “fundamentally disagree[s]” with Mello on what his party euphemistically calls women’s reproductive health. In his statement, Perez also affirmed that every Democrat candidate should toe the pro-choice line. All of which led to Mello promptly selling out his pro-life supporters in an interview with HuffPo. So there you go.  

But the backbiting didn’t end there. Dozens of outlets on the left immediately took to calling Mello “anti-abortion” despite his 100% rating from Planned Parenthood. New Republic cited Mello as evidence of the party being “willing to go squishy on abortion to win elections.” That sentiment—along with a fair amount of anti-Catholic suspicion—was echoed in piece after piece, along with sound rejections of compromise or pragmatism on the issue. Astonishingly, it was Rolling Stone that offered the most flexible position: it’s fine for there to be pro-life Democrats, so long as they don’t do or say anything that might suggest they are pro-life.

I don’t know what this portends for the Democrats, only that it furthers their trend toward ideological purity. It reminds me of the Tea Party’s demands for purity, except more narrowly focused. At present, the Democrats seem to only have three issues: 1) resist Trump, 2) pussy-hat rights, and 3) girls who are boys, who like boys to be girls, who do boys like they're girls, who do girls like they're boys. (Bonus if you name the title and artist.) That probably helps explain why a little mayor’s race in a solidly red state seems like a big deal to them.