I don't think they will spend a ton of time trying to paint her as crazy. The same policy failures that would've hit Biden will be linked to her. She will get hit extra hard over immigration since she was the Immigration Czar who only visited the border once.
Here's the thing though -- Biden also had a lot of policy wins, and a lot of the negative talking points fall apart once you have someone who can actually complete a sentence and articulate their position.
For example, you mention the border. It was a debacle for almost all of Biden's presidency and he polled horribly on it. But if you want to snapshot in time June 2019 (Trump) vs June 2024 (last month) border crossing are down about 15%. They're at their lowest levels since 2021. So someone who can actually speak can get on a debate stage and say rather easily "I did a great job getting the border under control, encounters at the border are lower now than when you were in office" and while that might be
spin that ignores a lot of post-COVID failures prior to this year it isn't even a lie.
Here are some other things Harris could easily hit on:
-The US economy is doing unbelievably well over the past four years relative to the rest of the western world
-Massive investment in infrastructure relative to Trump who talked a lot and did nothing
-Reduced drug costs, including capping insulin costs well below what they were previously
-Less uninsured Americans than ever before
-Major investments in American manufacturing led to 800,000 new manufacturing jobs and even if you adjust for COVID he still added more manufacturing jobs from post-COVID than Trump did pre-COVID *and* manufacturing is at it's highest levels in the US in 15+ years.
Where Harris loses is potentially on social issues like men playing women's sports, DEI, pro-Hamas crap, etc. that are all widespread unpopular in suburbs and areas where she needs to win. She's not going to outright lose a policy battle with Trump. They will both score points in different areas.