Donald Trump said he doesn't understand his recent drop in polls, but he continued his attacks on Ben Carson, who has knocked him from the top spot in Iowa and - in at least one survey - nationwide among Republicans.
Trump kept up his attacks on Carson, who is beating him handily in a series of four polls from Iowa and as of Tuesday morning overtook the top spot nationwide in the latest CBS News/New York Times poll.
Carson has previously said that he wanted to end traditional Medicare in its current form, but wrote over the weekend in a Facebook question-and-answer post that he would not end the highly popular program.
As a pediatric neurosurgeon, he would refer women to abortion providers in some cases, even though he personally opposed abortions, according to a 1992 article in The Baltimore Sun .