GLENDALE, Ariz. (AP) Vice President Kamala Harris drew on her prosecutorial background to make her first expansive pitch on immigration to border-state voters as she and her new running mate, Minnesota Gov. Tim Walz, attracted thousands to a campaign rally in Arizona during their tour of battleground states.

Harris, the former attorney general of California, reminded the crowd that she, as a law enforcement official, targeted transnational gangs, drug cartels and smugglers.

I prosecuted them in case after case, and I won, Harris said in front of a crowd of more than 15,000 in Glendale, a suburb of Phoenix. So I know what Im talking about.

Harris promoted a border security bill that a bipartisan group of senators negotiated earlier this year, which Republican lawmakers ultimately opposed en masse at Republican nominee Donald Trump s behest.

Donald Trump does not want to fix this problem, Harris said. Be clear about that: He has no interest or desire to actually fix the problem. He talks a big game about border security, but he does not walk the walk.

Her effort to address immigration a political liability that has dogged Harris for most of her vice presidency head-on in the critical battleground state is part of a broader push from her campaign to make gains in Sun Belt states that had become increasingly out of reach with Joe Biden at the top of the ticket.