Both Trump and Harris say they'll build more border wall. In this county, the parts have been waiting, and rusting, since 2021.

Back in 2018, Kamala Harris and other Democrats labeled then-President Donald Trump’s wall a vanity project that wasted billions of taxpayer dollars. Harris even went so far as to post online that the barrier was “un-American.”

Now, as a candidate for president, her border security plan includes filling in strategic sections of the wall along the nearly 2,000-mile southwest border, given her endorsement of the failed bipartisan bill that she now says is the foundation of her border policy.

Some of the materials to build that wall have been waiting, and rusting, next to the border since 2021. When President Joe Biden took office, he immediately halted border wall construction.

Mark Dannels, the sheriff of Cochise County, Arizona, which shares 83 miles of international border with Mexico, brought NBC News to remote areas of the border where construction materials were stacked near unfinished wall.

“So it’s been sitting down here for last 3 1/2 years, and we’ve been frozen in time here in Cochise County when it comes to our border,” said Dannels.

The number of migrants coming into the county has declined since Biden’s executive action went into effect in June, as is the case along the rest of the U.S.-Mexico border. The average monthly number of inmates in county detention involved in border crimes such as smuggling has declined by 23% since June, according to sheriff’s office statistics.

But the Tucson sector of the border, which includes Cochise County, remains the nation’s busiest for illegal crossings, and Dannels said his officers are still conducting high-speed car chases of U.S. citizens who are paid to smuggle migrants.

On Friday, Harris visited the border about an hour east of Cochise County. Even though Biden