Washington: The latest opinion polls conducted this week have shown that former Secretary of State Hillary Clinton and Vermont Senator Bernie Sanders are going to witness a close battle Nevada. It is notable that Clinton led by a wide margin in the state few weeks ago.

FiveThirtyEight reported on Friday: "Nevada is among the hardest places to poll in the nation, with a spotty track record to prove it. Going into the 2008 Republican caucuses, the polling average gave Mitt Romney just a 5-point advantage over John McCain; Romney ended up winning by 38 points. In 2010 when Republican Sharron Angle challenged Harry Reid, then Senate majority leader, for his seat, the polling average showed her beating the incumbent by a 3-point margin; she lost to Reid by nearly 6 points."

Some of the reasons for this track record: the odd hours that so many gambling-industry Nevadans work and Nevada has been doing caucuses for a decade. It may be recalled that previously primary was held in the state.

It remains to be seen whether the Nevada Caucus will actually be a close contest or not. We need to wait for Nevada Democrats to go to their caucus sites and do their thing.

The Iowa and New Hampshire are states not seen by many as the perfect benchmark to how presidential candidates will do in the rest of the country. This is a good news for Clinton's supporters. The former secretary of state was an overwhelming favorite for months but she barely won the Iowa Democratic Caucus and lost in New Hampshire primary.