Updated at 12:13 pm, Jan. 4 to reflect final entrance poll results.

Results for the Iowa caucuses came down to the wire with Mitt Romney, Ron Paul and Rick Santorum battling for the top spot. The repeat contenders, Paul and Romney have seen some big shifts, but also eerie consistency.

Final entrance poll results show Paul doubling his support level since 2008 while Romney’s has remained the same.

Paul has made big gains across most groups, but two groups stand out -- young voters and independents. Paul wins a double bonus; he garners a greater share of votes in these groups and more of them are turning out compared with 2008.

The biggest improvement for Paul is among young voters. He is now winning about half of voters under age 30, up from about one in five in his last effort. Although still a relatively small proportion of all caucus-goers (11 percent in 2008), young voters have increased their share of the electorate to 15 percent.

Paul has made big strides among independent voters too. More than four in 10 independent voters support him, up from three in 10 in 2008. And almost a quarter of voters identify as independents this year -- nearly doubling their share of the 2008 electorate.

For Romney, his support levels have changed very slightly since 2008. He can point to a few improvements but he also has a few places where he’s slipped. Notably, he’s not budged among Republican voters. He has seen a drop among the most conservative voters, down nine percentage points. But he’s made up for it with increased support among more moderate voters.

In 2008, Romney’s support was consistent across age groups. This time, Romney’s support skews older with more than double the support among seniors as among those under age 30.

The ace up Romney’s sleeve this year is his perceived electability. About three in 10 Iowa voters say beating President Obama is the most important candidate quality. Romney wins roughly half of these voters, dwarfing the other candidates.This was Romney’s strong suit in 2008 as well -- he won 51 percent of the vote in this group -- but electability was a much lower priority for caucus-goers at that time. Just 7 percent said the most important personal quality was someone who “has the best chance to win.”

These are final results from the Republican caucus poll of 1,787 voters as they entered 40 randomly selected caucus voting places in Iowa on Jan. 3, 2012. The poll was conducted by Edison Media Research for National Election Pool, The Washington Post and other media organizations. The results for typical characteristics have a margin of sampling error of plus or minus four percentage points.

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