You have [Donald] Trump and [Ted] Cruz battling it out, and the moderate establishment candidates like Chris Christie or Jeb Bush, Marco Rubio, John Kasich - they have formed a circular firing squad.

Hillary Clinton is also not a very exciting, inspiring candidate to a lot of the left-leaning Democratic base, especially in Iowa.

Michael Rubio said Trump's plan was impulsive and not well thought out. The other thing that's really annoying Republicans is that this was supposed to be their great week. The president gave a speech on terrorism that was not well received. They were working hard to tie Hillary Clinton to the president. Then along comes Donald Trump, and the story changes dramatically.

Until he announced his immigration policy last week, Obama had the support of most Hispanic voters - but not the enthusiasm they had shown for him in 2008. That may be changing in part because of the decision not to deport young immigrants whose undocumented parents brought them here as children.

Donald Trump has said he wants to keep Medicare and Social Security the way they are. Congressman Price along with most Republicans are on record supporting voucherizing Medicare. So there are going to be some conflicts to resolve there.

[Donald] Trump's path to victory depends on getting historic levels of support from white voters, and particularly large numbers of white, non-college-educated voters.

Republican candidates have won whites with college degrees in every presidential election since polling began.