Qualified immunity is a well established legal principle, Alito and Roberts would be voting against the rule of law and system of justice if they voted to end QI. QI is a nessecary part of the criminal justice system.
Your knowledge is sorely lacking on this. Qualified immunity is not a rule of law, it is a doctrine the Supreme Court invented in 1982 in
Harlow v. Fitzgerald, and expanded and strengthened in subsequent cases. It says, in essence, that in any claim against government misconduct, government actors are automatically protected against suit unless extraordinarily high hurdles are topped by the plaintiff, requiring information and evidence typically sealed by the very agency that would be sued. It creates a burden of proof far above and beyond that possessed by the state, merely to establish standing. It is derived from 42 USC 1983, but exists nowhere in actual federal law. Indeed, 42 USC 1983 was enacted in 1871 as part of the Civil Rights Act of 1871, with the express purpose of giving victims a path to seek redress for government misconduct, and not until
111 years later was qualified immunity invented from it, a doctrine wholly contrary to the purpose of the statute. It is a doctrine unique to the United States, and within the last 30 years. This is not some foundational principle of Common Law, with eons of august tradition. This is a new and destructive invention of an activist court, and Alito has been foremost among those expanding and strengthening it. It is fawning service to the law enforcement industry.
And we haven't even discussed the effective absolute immunity that prosecutors enjoy and take advantage of.
No one who endorses a doctrine, codified in law or otherwise, that sets apart special protection for government actors can pretend to any regard for the Constitution, let alone claim any love of liberty.