In the latest “believe it or not” moment, farmers are experimenting with collars for cows equipped with GPS and electronic signaling that would eliminate the need for fencing and herding. American farmers spent $300 million last year on fencing. To policymakers concerned about the creation of jobs, did anyone see farm fencing falling to the veracious appetite of disruption? The Republican Party, led by Donald Trump, is unabashedly lurching backwards. The tax bill was straight out of the supply side 1980s. The steel tariffs are from the Smoot-Hawley 1930s. Democrats are, understandably, mostly in opposition mode. But the world is...