Immigration and border security are top issues in Arizona, the only battleground state that borders Mexico and one that contended with a record influx of asylum seekers last year. Trump has an edge with voters on migration, and Harris has gone on offense to improve her standing on the issue and defuse a key line of political attack for Trump.

Vice President Kamala Harris is making her first visit to the U.S.-Mexico border since becoming the Democratic presidential nominee. She walked a scrubby stretch of fence line near Douglas, Arizona,

The Democratic presidential candidate is seeking to project an image of strength against illegal migration as she confronts one of her biggest vulnerabilities in the November election.