LOS ANGELES — Was it something we said?

In the six months since President Trump took office, he has visited Iowa. Ohio. Florida. New York. South Carolina. Wisconsin. Georgia. Pennsylvania. Virginia. Michigan. Tennessee. Even New Jersey.

But the 39 million residents of the country’s most populous state have yet to receive a visit — a break in presidential travel history that dates back decades.

Perhaps Mr. Trump is in no rush to visit the state that has emerged as the center of the resistance to his presidency. He lost California by more than four million votes in November. The state is the biggest Democratic stronghold in the nation, and its leaders have been challenging Mr. Trump and his policies at every turn. Mr. Trump even described California as “out of control.”

Or maybe it’s the president’s apparent aversion to long trips. Despite having the luxury of traveling on Air Force One — no taking off your shoes for a security line — Mr. Trump has stayed close to the East Coast since he took office, crossing the Mississippi River only once, briefly, for an Iowa rally last month.