A new school year in the United States has begun with a touch of controversy.  It surrounds a welcome back speech to students from President Barack Obama that was seen in classrooms around the country.  In some communities, parents staged a boycott of the president's address - an example of how politically divided the nation has become.

The president's message to students was simple:  study hard, pay attention in class and embrace the opportunity to learn.

"We can have the most dedicated teachers, the most supportive parents and the best schools in the world.  And none of it will make a difference; none of it will matter, unless all of you fulfill your responsibilities," Mr. Obama said.

It was a presidential pep talk delivered at a time of economic uncertainty for many American families.  Mr. Obama said he understands the tensions many students face.

"The circumstances of your life - what you look like, where you come from, how much money you have, what you've got going on at home - that's no excuse for neglecting your homework or having a bad attitude in school.  That's no excuse for talking back to your teacher or cutting class or dropping out of school.  There is no excuse for not trying," he said

Mr. Obama spoke at a high school in Arlington, Virginia - a short drive from the White House - where the student body is ethnically and economically diverse.  His message was broadcast far beyond the campus of Wakefield High to classrooms around the country on the Internet and cable television.

Critics of the president denounced the speech as an effort by the White House to promote the president's domestic agenda.  Some parents told their children to boycott the address.

This Colorado student stayed away.

"It's just a family decision to not come.  I think our parents should be the ones to push us more in our education and what not than the president," the student said.

But this mother in North Carolina said she thought the speech could have a positive impact.

"When kids get to hear something about motivation from someone like that, it's fantastic," she said.

The White House took the unusual step of posting the president's remarks on its website 24 hours before the speech was delivered.  Spokesman Robert Gibbs said the address was simply meant to give students a boost at the start of a new school year.