Nevada's Democratic caucuses are only a week away, but it's really unclear who has an advantage in the state.

According to HuffPost Pollster, which aggregates publicly available polling data, Sen. Bernie Sanders (I-Vt.) and former Secretary of State Hillary Clinton are tied in the polls ahead of the state's Feb. 20 caucuses. But it's unclear how reliable that data is, given how little polling has been done in the state. A poll released this week showing Clinton and Sanders tied was the first survey of Democratic voters in the state since December.

"We haven't been doing this that long, there's no real sense of the caucus electorate the way there is in Iowa," said longtime Nevada journalist Jon Ralston on "The Rachel Maddow Show"on Friday. Ralston also noted that turnout at the Nevada caucuses has been particularly low in the past and that Democrats have same-day registration in the state, making it difficult to predict who is going to vote.

Nevada, at the urging of its influential senator, Harry Reid, moved up its caucuses ahead of the 2008 election to be one of the first states to pick a presidential nominee.

The New York Times noted that same-day registration could particularly benefit Sanders, given that they tended to support him in Iowa.

Nevada voters are demographically diverse. Voters of color will comprise 39.4 percent of the state's electorate in 2016, while Latino voters are expected to make up 21.2 of the voting population, according to data from the Center for American Progress Action Fund.

Nevada has been described as a firewall for Clinton and she has been building up her campaign presence there since April, while Sanders only started in the fall. The Times reported that Sanders recently flew in staff from Iowa to add to a 90-person operation in place in the state.

Clinton may have an advantage in Nevada, given that she won the popular vote there against President Barack Obama in 2008, despite getting fewer delegates than he did. Clinton's presidential campaign manager Robby Mook, also ran her 2008 campaign in the state.

Republicans in Nevada will hold their caucus after the Democrats, on Feb. 23.

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