The impact of judicial review has been to make the Supreme Court an important actor in some of the most contentious issues of our time. This was true at many points in our history. Today, the Supreme Court is the subject of great political debate because of the power of judicial review.
Because the Supreme Court has the power of judicial review, it can inject itself into important issues. It did this on the issue of slavery in the Dred Scott case. It did it when it struck down (and later upheld) New Deal legislation. The Warren Court did it when it got involved in such things as civil rights and civil liberties. Today, the Court is deeply involved in issues of abortion. It has recently had to decide on the issue of the government mandate that everyone get health insurance under "Obamacare." In all of these ways the presence of judicial review has had a major impact on American politics and society.