Second Obama-Romney US presidential debate starts

President Barack Obama and Republican presidential candidate and former Massachusetts Gov. Mitt Romney participate in the second presidential debate at Hofstra University in Hempstead, N.Y., Tuesday, Oct. 16, 2012. AP /Charles Dharapak

HEMPSTEAD, New York — President Barack Obama and his Republican challenger Mitt Romney shooks hands on Tuesday at the start of their second televised national debate ahead of the November 6 election.

The Democratic incumbent is generally regarded as having come off worst in the pair’s first head-to-head encounter on October 3, and polls suggest the race is extremely close with only three weeks until polling day.