What Tricia Cotham's switch says about N.C. politics

This unprecedented look inside the Democratic Party is deeply unsettling - and gives Republicans a historic opportunity

Perhaps the final straw for N.C. Rep. Tricia Cotham came in the aisles of Target. 

The Mecklenburg Democrat and her son were wandering the toy aisles, checking out Nerf guns and remote control cars, when a woman came out of nowhere to accost them.

"She cussed me out, up and down, screaming at me," Cotham said last week. 

Her infraction? Failure to fully obey the Democratic Party.

In an emotional press conference at the NCGOP headquarters, Cotham announced Wednesday that she is changing her party registration and joining the Republican caucus in the House. 

In doing so, she pulled back the curtain on intraparty politics in an unprecedented way — giving us a glimpse of what the Democratic Party has become under Gov. Roy Cooper.

The news sent shockwaves through the North Carolina political landscape and even grabbed headlines nationally. For good reason, though not the one you might think.

While Cotham does represent the 72nd Republican in the state House, a supermajority of the chamber, she is…