The solution is for Republicans and Democrats to unite in supporting a constitutional amendment that fixes the size of the Supreme Court at its current nine justices, each of whom would serve an 18-year nonrenewable term, staggered so that one seat opens up during the first and third years of a president’s four-year term. One-term presidents would be guaranteed two appointments; two-term presidents would get four. Each two-year Senate session would consider a nominee.
Given the length of this term, longer than for judges on the high courts of any other constitutional democracy, the justices would be amply independent.
Presidents would no longer have the incentive to pick comparatively young nominees — say, someone 45 to 50 years of age — to project their influence decades into the future. Justices would lose their power to help pick successors who share their views by retiring strategically.