SAN FRANCISCO (CBS SF) — Half a million immigrants who applied for naturalization in the United States this year — hoping to vote in a national election in which immigration has been a dominant issue — aren’t likely to be able to vote due to slow processing of applications.

It came as no surprise to the U.S. Citizenship and Immigration Services (USCIS) that 2016 would see a massive influx of applications for U.S. naturalization due to the upcoming national election. The White House Task Force on New Americans even launched a citizenship-awareness campaign to encourage the 8.8 million lawful permanent residents eligible for citizenship in the U.S. to apply.

USCIS officials also anticipated a major increase in applications due to a pending naturalization fee increase expected later this year. A similar increase occurred prior to the 2008 election.

“They should urgently redistribute pending cases to field offices with capacity and/or deploy supports to stressed offices,” writes Tara Raghuveer in a report released Friday that describes how the slow application process, and resulting backlog, may cause voter disenfranchisement this election cycle.

Raghuveer, the deputy director of the National Partnership for New Americans, a coalition of 37 immigrant and refugee rights groups, said she was shocked to learn how few applications had been processed. She described the backlog as “absurd.”

Many immigrant rights organizations rushed to get eligible immigrants in swing states to apply for naturalization early in the year to allow sufficient time for processing of the applications before states’ voter registration deadlines.

Of the more than 500,000 applications pending nationwide, roughly a fifth of those applications are in California.

California’s voter registration deadline for the upcoming election ends on October 24, so many potential California voters may not get their applications processed in time.

As of mid-September, San Francisco had over 16,000 U.S. citizen naturalization applications pending, more than any other USCIS field office in the state.

USCIS’s San Francisco spokeswoman Sharon Rummery said pending applications in San Francisco can take up to seven months to process.

Raghuveer said California isn’t nearly as troubling as Nevada, where some applicants who submitted their paperwork in January say they still haven’t been able to meet with immigration officers.

Nevada is not keeping up with the increase in applications. California’s backlog increased by only 30 percent while Nevada’s backlog has almost doubled since 2015. Likewise, Florida has seen a backlog increase of almost 60 percent over last year.

USCIS officials in Nevada did not immediately respond to CBS San Francisco’s inquiries regarding the cause of the backlogs in that state.

By Hannah Albarazi – Follow her on Twitter: @hannahalbarazi.