Leonard S. Rubinowitz believes that Dawn Clark Netsch would offer this advice to law students weighing careers in public interest.“Do it.”Students at Northwestern University School of Law now have more opportunities to pursue such work. The school announced Tuesday that the estate of Netsch — the longtime Illinois political trailblazer who died in 2013 — gave $5 million to the law school for scholarships to students seeking careers in nonprofits and government.The money will also help graduates …