Because it would decide the fate of Affirmative Action, racially bias policy against Asian, especially Chinese Americans
Current US Supreme Court :
4 Conservatives who are against Affirmative Action:
Justice Clarence Thomas,
Justice Antonin Scalia,
Chief Justice John G. Roberts,
Justice Samuel A. Alito, Jr.
Justice Anthony M. Kennedy, who sometime liberal and sometime conservative or so-called swing vote
4 liberal Justices who are for Affirmative Action
Justice Ruth Bader Ginsburg.
Justice Sonia Sotomayor,
Justice Stephen G. Breyer,
Justice Elena Kagan.
But Conservative Justices Scalia, Thomas and Justice Kenndy are very old. So is liberal Justice Ruth Bader Ginsburg.
During next 4 years or so, at least 2 of them would retire from bench. Most guess is that Ginsburg, Scalia or Kennedy retire. Next US President would have big chance to tip the balance of Supreme Court:
1) If Hillary is elected, she will defintely nominate liberal justice(s) who is certainly for Affirmative Action. If it happened, Chinese Americans and their children would live under Affirmative Action for generations to come for sure.
2) If a Republican President is elected, he would do the opposite to nominate conservative justice(s) who will certainly get rid of Affirmative Action for good.
So think hard before you vote.
Remember, Supreme Court Justice serve life time, while US President for 4 or 8 years