You can't just state something as fact and not show your work. You are making a claim it's up to you to support it. You can't just go around saying "I'm right unless you prove the negative".

You have not placed any goalposts to begin with, what is your definition of "better"? By what metric are you using? What do you mean by "under the Democrats"?

How about we define "better" as "death rate per capita within immigration detention centers"? And "under the Democrats/Republicans" as "who holds the executive branch"? We should see an increase during the Bush years, when ICE was first created, a decrease during the Obama years, followed by an increase during Trump's first term, decrease during Biden, and increase under Trump's second term right?

Is that what happened?

If you don't like my attempt at making your claim falsifiable, which I suspect you won't; especially when you see the results, feel free to redefine your lose language into something else rigid and falsifiable. Set those goalposts.