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 deputized her to take on the root causes of immigration in 2021, she had only visited the border once previously during her time as vice president.

The Harris campaign is quick to note that Harris’ approach to the border began with her law enforcement leadership in California. “As attorney general of a border state, Vice President Harris prosecuted transnational criminal organizations for the trafficking of guns, drugs, and human beings,” said Mia Ehrenberg, a campaign spokesperson, via email to NBC News. “Americans want leaders like Kamala Harris who fix problems, not politicians who only want to campaign on them like Donald Trump.”

When pressed on her immigration policy, Harris pledges to revive the bipartisan border security bill that failed to pass Congress in late May after Trump urged his supporters to reject it.

“Vice President Harris believes in tough, smart solutions to secure the border, keep communities safe, and reform our broken immigration system,” Ehrenberg said.

The border bill would have provided 1,500 more border personnel, upgraded technology and kicked off the “immediate resumption” of the border wall construction that was underway in 2021, according to its text.

“A border wall is something that Vice President Harris supports, but only where it makes sense,” said Arizona state Rep. Consuelo Hernandez, a Harris supporter whose district includes a southeastern chunk of the Arizona border with Mexico.

Hernandez said the wall should be seen as just one part of the border security effort that Harris would pursue, not as a panacea. “We need a wall and resources,” she said. “That means making sure that we have more ICE agents and Border Patrol. It means making sure that we have judges who can process asylum cases a lot quicker.”

Trump raises immigration in every campaign speech, describing his plan for the mass deportation of more than 10 million migrants and applauding his own record on wall construction. Trump built more than 450 miles of wall, though nearly all of that total was the replacement of existing barriers with new, taller wall.

In 2023, the Biden administration sought to waive environmental laws to proceed with wall construction in the Rio Grande Valley of Texas. The move was met with backlash by some immigrant advocates, who said Biden was changing his position. The Biden administration said it was required to spend money already allocated for wall construction during the Trump administration. Still, no new wall construction has begun in the Rio Grande Valley or anywhere under the Biden administration.

“I want to see it finished,” said Border Patrol agent Art Del Cueto, who also serves as the vice president of the National Border Patrol Council, an agents union that has endorsed Trump.

Del Cueto says the wall acts as a deterrent, and prior to the wall being built in remote yet high-traffic areas like Cochise County, there were some sections where the border was only marked by a few strands of barbed wire.

Del Cueto’s union supported the bipartisan border bill that is the basis for Harris’ border plan.

“What I would say to Vice President Harris is she’s been there for 3 1/2 years. She should have had some type of targeted approach, or some type of approach when they took office,” he said.