I am against any change that would rejigger the basic balance created by the separation of powers that has worked pretty well so far. The Supreme Court does seem overly politicized right now, but that's because we're just in a period right now where every branch of government, heck the entire country and every facet of life, is overly politicized. Setting up regularly scheduled pitched battles over Supreme Court appointments while watering down the independence of the judiciary isn't going to fix that.
What separation of powers? Every single Constitution based on the US constitution has ended in presidential dictatorship or outright military coup (often the former followed by the latter) because our constitution doesn't actually meaningfully separate powers. The judiciary is often complicit in this, especially our actual judiciary which has pretty much consistently upheld executive prerogative on every issue, both domestic and foreign.
Almost all laws made today are administrative law, which is made entirely inside the executive branch with input from America's most powerful corporations as represented by large law firms in the agency rule-making process.
Obama has actually dramatically changed a lot of American energy, environmental, and regulatory policy - changes that took place exclusively within the executive branch w/ the consultation and consent of corporate America. This is because our judiciary has molded for us a system of government they modeled after the German Empire, which unsurprisingly eventually died as a military dictatorship.
The court is intensely politicized, but it doesn't mean it's actually democratic. Americans seem to conflate politics and democracy, which would make a lot more sense if they actually lived in a democratic republic.