What are the theories on how aboriginal people got to the Americas?

Early Asian boats may have navigated across the north Pacific and along the American west coast as far down as Mexico or more.

I just saw a Discovery channel program on this. They did a genetic trace on Native Americans and found that most were linked to a tribe in Mongolia. Also there wasn't a lot of variation, so now they think that there weren't "waves" of immigrants, but rather a few tribes that expanded, varied, and warred with each other for dominance. (This is a very, very simplified synopsis, I know.)

The only plausible path is over the Bering land bridge. Unfortunately, I have no specific references.

well they're finding pre clovis sites back east that seem to have the same style of points that are found in France, so i suppose there may have been a land bridge from europe as well, but the archaeologists where I live dont like to talk much about "Pre-Clovis"