Meet Samuel Alito, the Most Important Conservative in America Today

Easy to forget but hard to ignore, the 64-year-old justice is leaving an indelible mark on the Supreme Court. And giving liberals a lot to complain about.

Supreme Court Justice Samuel Alito enraged liberals twice on Monday, handing down two potentially wide-reaching opinions that weakened Obamacare's contraception mandate and severely undermined public unions.

Alito is a reliable member of the Court's conservative flank, though he often earns less attention than his irascible counterpart Antonin Scalia, whose opinions are regularly dotted with sensational rhetorical flourishes that easily seize media attention. Alito is less waffly than either Chief Justice John Roberts or the streaky, libertarian-at-times Anthony Kennedy, and he doesn't possess any cartoonish idiosyncrasies akin to the "disgraceful silence" of Clarence Thomas, who for eight years and counting hasn't asked a single question during an oral argument.

Alito, an Italian-American from New Jersey, can be easy to forget. But as Monday again showed, his significance on the Supreme Court is real, and worth remembering.

George W. Bush's nomination of Alito in 2005 to replace Sandra Day O'Connor (by then a swing vote) on the Supreme Court may end up being one of 43's most long-lasting and impactful decisions. Consider that in the last year alone, Alito has weighed in on issues as diverse as same-sex marriage, voting rights, unions, and, of course, Obamacare. And in many of those cases, his was the decisive vote — though the vote did not always work in his favor.

Confirmed on a 58-42 vote by the Senate, Alito's Republican support was near unanimous — and his opposition by Democrats almost equally partisan. His conservative bona fides have prompted some to nickname him "Scalito" (a play off of "Scalia" and "Alito"), and he's done little on or off the bench to dispel such notions. During the 2010 State of the Union Address, Alito famously mouthed "not true" when President Obama condemned the Court's Citizens United ruling on campaign finance. He's been a scarce site at the annual speeches since.

Alito is also quickly becoming a dirty name among progressives, who view his ideology as anti-women. Last year he wrote the opinion for Vance v. Ball State University, which made it more challenging for women to sue employers for workplace harassment.

At 64, Alito, like his Bush-appointed brother-in-arms Roberts, is a relatively young member of the Court, and will likely serve for another 20 years, barring any health complications. Liberals, beware: Monday may just be a preview of what's to come from Alito in the years ahead.