Bernie Sanders’ poll numbers may have seen a dramatic surge as the Democratic race for nomination heats up, but millions of ineligible voters in two of the biggest states, New York and California, could hurt the Vermont senator’s chances against fellow presidential rival Hillary Clinton.

A string of polls have either seen Bernie Sanders closing the gap on Hillary Clinton nationally, or have seen him surging past her to establish a lead of his own. According to a new NBC/WSJ poll released Monday, Sanders pulled within two points of Clinton nationally — 48 percent to Clinton’s 50 percent — in what has been the Vermont senator’s best performance yet.

Moreover, the poll highlighted Clinton’s waning appeal among female, black and elderly voters — all traditional Clinton strongholds. Another report published in the Inquisitr showed how female voters, who were earlier Hillary Clinton’s supporters, are now switching sides to vote for Bernie Sanders.

Yet another poll conducted by Bloomberg showed that Democratic voters are evenly split nationally, while a poll by PRRI/The Atlantic showed Sanders surging ahead of Clinton by one point after having trailed her by 20 points when the poll was last conducted in January.

And while all of this will come as great news to Bernie Sanders, there remains a catch which could cost him dearly in the race.

According to Salon, millions of Bernie Sanders’ supporters are ineligible to vote — both in New York and California. This is due to the fact that they are not affiliated to the Democratic Party or the Republican Party, meaning they are Independent voters. This situation is further complicated by the fact that News York’s closed primary system had a severe requirement that voters seeking to change party affiliations in order to vote in the primary had to do so by October of last year, which has left approximately 3.5 million Independent voters without a voice in the state’s primary.

An earlier report in the Washington Post pointed out that a heavy percentage of Bernie Sanders’ supporters are made up of Independent voters. In Michigan and Oklahoma, for instance, Hillary Clinton lost to Sanders despite leading by double digits among affiliated party supporters. There is no knowing to what degree New York’s Independent voter-base, constituting 27 percent of the electorate, could have swayed the race in Sanders’ favor.

It is quite evident that a lot of voters, who did not identify with the Democratic Party up until only a few months ago, are now willing to vote for the Vermont senator. While the figure of Independent voters is extremely high in New York, the situation is strangely grim in California.

Approximately 500,000 voters in California, a blockbuster new report found out, are registered with the ultra right-wing American Independent Party without their knowledge. According to an L.A. Times investigation, “fewer than 4 percent could correctly identify their own registration as a member of the American Independent Party.”

Hillary Clinton may still be confident of outperforming Bernie Sanders on account of millions of independent voters who are not allowed to vote in New York's Tuesday primary. (Photo by Alex Wong/Getty Images)

While California voters still have a chance to change their party affiliation, New York’s closed primary system means that Independent voters have little hope. However, a last-minute lawsuit was filed Monday for an emergency declaratory judgment deeming millions of voters whose registration was switched from Democrat to unaffiliated, eligible to vote on Tuesday.

“This is our attempt to provide a means of recourse for those thousands of New York voters who find themselves in this very frustrating position, and to raise awareness about the need for a new level of accountability in the electoral process,” said Shyla Nelson, a spokesperson with Election Justice USA, which filed the lawsuit.

While it remains likely that the move by Election Justice USA might get some disenfranchised voters back their right to vote, it appears highly unlikely that all of the 3.5 million Independent voters will get a chance to vote in today’s New York primary, which will be a huge blow to Bernie Sanders’ chances in the state.

[Photo by Alex Wong/Getty Images]