Since the start of the Biden administration, Gov. Greg Abbott of Texas has mounted an increasingly brazen challenge to the federal government over immigration, questioning the notion, long upheld by federal courts, that it is Washington, and not border states, that sets immigration policy.Mr. Abbott has been able to notch some important victories, pushing the boundaries of what a governor can do when it comes to immigration enforcement.With the support of the Republican-dominated Texas Legislature, he has poured more than $10 billion into a long-term deployment of state police and National…