I think it would. The court has had a 5-4 (quasi-)conservative/liberal breakdown since at least early 1990s A lot of the seminal decisions over that time period -- cases involving the commerce clause, the freedom of religion, the freedom of speech, the right to bear arms, fourth amendment cases, federalism, partial birth abortion, section 5 of the 14th amendment -- were 5-4 decisions involving interpretations of the constitution. It is generally thought that starie decisis is at its weakest in cases involving constitutional (as opposed to statutory) interpretation, so a 4-5 realignment could drastically alter decades-long expectations in many different areas of the law. Constitutional law, in particular, gains part of its legitimacy through permancy, and people order their lives, affairs, and businesses according to the laws in place at the time. I have no doubt that a 4-5 court would attempt to systematically dismantle all of the 5-4 holdings issued over the past 25 years. That kind of a sea change in the SCOUTUS could be monumental.