Why are we allowing Hugo Chavez into our country?

How do two foreign dictators (Chavez and Ahmadinejad) who have declared death to America and have likened our very own president to the "devil" and "Hitler" be allowed to come onto American soil and continue with their anti-American rhetoric with no repercussion whatsoever? Now, Hugo Chavez is in Harlem, NY continuing with his agenda and actually received a standing ovation. He is inciting an insurrection by doing this.