It's the states vs. their cities.
The issue: Illegal immigration.
A growing number of proposed state laws designed to crack down on sanctuary cities are putting local leaders in those municipalities on the defensive, forcing many to fight off measures they say could cripple their crime-fighting abilities and threaten economic growth.
At least 31 states are considering legislation this year that would ban sanctuary policies, according to the National Conference of State Legislatures. Many of those bills face fervent opposition from mayors and other officials of progressive cities.
The battle unfolding between state and city lawmakers is largely the result of a broader national question that President Donald Trump has made front and center: How should the government deal with legal and illegal immigration?
"Our current immigration laws are outdated and dysfunctional" and that has resulted in states and cities trying to address immigration issues in competing ways, said Avideh Moussavian, a senior policy attorney at the National Immigration Law Center.
"Localities know these populations benefit them economically and want to protect them," she said, adding that "many states tend to think there is some clean and orderly fix, like a 'ban,' which is ridiculous."