Problems on the South border are essentially linked to budget. Since the Ukraine support and border funding bills were passed, more border guards were recruited and the number of arrests at the South border has halved. The fault is with maga reps who stalled funding so Trump can criticise Biden's administration.
Didn't Trump pull every trick to extract money from every possible budget to build a wall after the dems blocked every attempt to get the money by normal means? What did Kamala do to try to get the money to finish the wall? When it got close to this election, I seem to remember some token gesture to build a bit more, but I can't remember her name being mentioned.
If you research, you can find all sorts of cope articles from the normal leftwing press, saying things like she said, " don't come" and she had a good relationship with the various countries the immigrants came from, and she spent a lot of time trying to persuade them to keep their citizens, but the facts show that she was an abject failure as far as controlling the Southern border, which was her job to secure. It's roughly 4 times as much today compared to when she was appointed.
Also, regarding the blocking of the immigration bill, six Democrats voted against it. If they had voted for it, the result would have been 49-44 in favour. Why did they vote against it? Anyway, they didn't need a bill, they could have appropriated the money from anywhere to finish the wall, like Trump had to, if they were serious.
As I said, I can't remember a single thing she did to secure the border, which is the main point, and it's what the Trump side will use against her: If the border got 4 times worse and that's the only job she had, what happens when defence, cost of living, health service, accomodation, etc become 4 times worse when she's in charge. It's too easy!