While Donald Trump was imploding, primary voters in Kansas went to the polls Tuesday determined to end that state's disastrous experiment with conservative "supply-side economics." At least 13 conservative legislators were defeated in Republican primaries by their moderate opponents, including the Senate majority leader, and conservatives were trailing in several other races. (Several other conservative legislators had simply chosen not to run, seeing the tsunami headed their way.)

"Brutal. Brutal. Brutal." one conservative legislator told the Wichita Eagle-Tribune as he watched the returns coming in. "Absolutely brutal."

Gov. Sam Brownback, once mentioned in conservative media as a potential presidential candidate because of his success in tax-cutting and because of the economic boom that was certain to follow, wasn't on the Tuesday ballot. But with so many of his allies defeated, and with a 15 percent job-approval rating, the voters' disgust with his approach is nonetheless clear. It has produced nothing that its advocates promised, and just about everything that its critics warned against.

Now, moderate Republicans hope to join forces with Democrats in the upcoming Legislature to force a major change of policy direction, and after last night they now have the numbers to do so.

Speaking of numbers, let's review the results of this supply-side experiment of huge tax cuts for the wealthy and for business:

  • Per capita income growth in Kansas last year ranked 49th in the country, after ranking 12th prior to the supply-side regimen implemented by Brownback and his economic "guru," Arthur Laffer.
  • Income tax revenue has fallen significantly and has never come close to returning to 2010 levels. (And remember, 2010 revenues were already dismal because of the recession.
  • In late July, with the Kansas budget splattered with so much red that you'd think it was written at a Tulley-Frey wedding, S&P downgraded the state's bond rating for the second time in two years.
  • Monthly state tax revenue continues to come in below already-meager projections, forcing ever deeper and seemingly never-ending cuts in schools, transportation, state pensions and other government programs. Thousands of teachers have been laid off; schools have closed early.
  • In 2015, the state added a total of 9,400 jobs, while 2.6 million were created nationwide. Total job creation has badly trailed national numbers for the past five years.
  • State GDP growth also is considerably slower than nationally, and state exports are down 6.3 percent.

Of course, the importance of this story extends well beyond Kansas. Had the experiment succeeded, national Republicans and conservative media were poised to celebrate it as laboratory proof that supply-side economics ought to be implemented at the national scale, in Washington. And despite its clear failure, and despite growing bipartisan, populist outrage at income inequity, the GOP continues to base its entire economic policy on massive tax cuts for the wealthy accompanied by significant cutbacks in programs that give the working and middle classes some sense of economic security and stability.

Call it the Kansas Plan.  Call it a disaster.