A liberal would never elect a conservative and vice versa, but there&#x27;s an expectation to maintain the court&#x27;s approximate balance (which is why Scalia&#x27;s death is such a big deal).   So if a very right-leaning justice stepped down under a liberal president, he&#x27;d elect a center &#x2F; center-left justice. If the most left-wing justice in the world stepped down, then a left-wing president could elect the most left-leaning person.<p>By no means a rule, but a tradition at least.