What the entrance poll told us about Iowa's outcome In an election that produced a nail-biter finish between former Massachusetts governor Mitt Romney and former Pennsylvania senator Rick Santorum, here's what we can say about Tuesday night's Iowa caucus participants, based on interviews conducted with a sample of them as they entered their precinct caucuses. One caveat: caucus goers could have changed their minds once they got inside their precinct caucus and heard pitches from candidates or their surrogates, but this sample is the best evidence we have of why voters made the choices they made on Tuesday night. Ideologically, nearly half of the caucus goers called themselves "very conservative" and Santorum was the leader among those voters, winning one more than one out of three of them. Santorum also did best among those Iowa caucus goers who said that the most important issue was abortion. Older people tended to vote for Romney; the young voted for the oldest candidate in the field, 76-year old Texas congressman Ron Paul. The wealthy favored Romney, while the less affluent tended to back Paul. The people who above all were looking for a candidate whom they thought could beat President Barack Obama in November opted for Romney, indeed he did better among them than among any other category of voters in the poll. But the ideological purists who said what mattered most in selecting their candidate was finding the "true conservative" backed either Paul (37 percent) or Santorum (36 percent). Romney won only 1 percent of such ideological purist voters. Religious identification was an important factor in Tuesday night's outcome, but evangelical or born-again Christians - who accounted for nearly three out of five caucus attendees - did not consolidate behind one candidate. Instead, they scattered their votes, with 32 percent supporting Santorum and 18 percent Paul - while smaller percentages favored former House Speaker Newt Gingrich (14 percent), Romney (14 percent), Texas Gov. Rick Perry (14 percent), and Rep. Michele Bachmann of Minnesota (6 percent). But Romney dominated among the 43 percent of caucus goers who said they weren't evangelical Christians: he won nearly 40 percent of them, with Paul taking 26 percent. Not surprisingly the Texas congressman and 1988 Libertarian presidential candidate did quite well among self-described independents who accounted for 23 percent of Tuesday night's caucus participants - winning 43 percent of such voters. Paul was also the strongest contender among first time caucus goers who accounted for about four out of ten attendees. He won about a third of their votes. Entrance poll interviews revealed that 15 percent of caucus goers were voters age 17 to 29, and 48 percent of them opted for Paul. But more significantly, more than one quarter of caucus attendees were age 65 and over and Romney was the winner among that group, winning three out of ten of them. Romney and Santorum split the votes of the middle-aged voters, those between 50 and 64, with Romney winning 26 percent of them, and Santorum getting 27 percent. Paul had strong appeal among lower-income people. A plurality of caucus attendees who described themselves as earning less than $50,000 a year backed Paul -- he won 31 percent of those voters. But two thirds of Tuesday night's caucus goers said they made more than $50,000 and Romney and Santorum split the votes of that group, Romney got 28 percent and Santorum got 27 percent of them. Romney did better among those who said they made more than $100,000 a year wining 36 percent of such voters. Caucus attendees interviewed as they entered their precincts were given an array of four issues to choose as the most important to them: abortion, the federal budget deficit, the economy, and health care. A plurality of voters chose the economy as the most important issue, and of that group, one out of three Romney. Fifty-one percent of the caucus goers said working in business was a better preparation for serving as president of the United States than working in government, and of that group 36 percent said they'd vote for Romney, who served one term as governor of Massachusetts, but spent much for his adult life in businesses such as Bain Capital.