Why is the poem the new colossus considered as an american classic today?

There a couple reasons - one is that the a passage of the New Colossus is etched into the Statue of Liberty at the base (representing America and what it was founded on) and secondly it is one of the most controversial yet powerful poems ever written about America. It describes how the Lady Liberty is Justice and that she's willing to accept strangers from foreign lands. It describes everything America was founded on and why America is great. This is why it is a classic.