Donald Trump's derogatory comments about Mexicans and his vow to build a wall along the southern U.S. border have failed to spark a surge in voter registrations among Hispanics living in key swing states, a USA TODAY analysis shows

The study looked at the 50 counties with the largest Hispanic population in 10 swing states and found that voter registrations in those counties have increased during the 2016 election cycle. But the gains simply mirrored the growth in the Hispanic population and did not represent a "Trump effect" — a rush to register by Hispanics who plan to vote against the Republican presidential nominee — as some Democratic and Hispanic groups had expected.

Overall, voter rolls in those 50 counties increased by 3.8% in the lead-up to the 2016 election, compared to a 3.5% increase during the 2012 election cycle. Those increases are explained by overall population growth (2.9% this election cycle and 2.7% in the 2012 period) as well as even faster growth in the Hispanic population, which has jumped nearly 10% since 2010.

The lack of a "Trump effect" is clearer in the few states that provide voter registration data specifically for Hispanics. In Florida, the number of Hispanics registered to vote has increased 14.6% during the 2016 election cycle, nearly identical to a 14.4% increase before the 2012 election.

The findings show that Hispanics will play a larger role in the 2016 election, as the country's largest minority group continues increasing its share of the U.S. electorate,which has grown from 10% in 2012 to 12% now.

The data make clear that Hispanic advocacy groups, the Democratic Party and party nominee Hillary Clinton have yet to take advantage of Trump's disparaging remarks and tough immigration enforcement views.

Ali Noorani, executive director of the National Immigration Forum, a Washington-based group that advocates for immigrants' rights, blames both political parties.

"Republicans are ignoring this growing electorate," Noorani said. "And these numbers show that Democrats are leaving a lot of votes on the table too."

The Trump and Clinton campaigns did not respond to requests for comment.

Analyzing how Hispanics are registering to vote across different states is difficult. The secretaries of state of most states publish the total number of people who have registered to vote and many break that down by party affiliation, but very few provide data that identifies Hispanic voters.

To get around those limitations, USA TODAY used data from the Pew Research Center to identify the five counties with the largest population of Hispanics in each of 10 swing states: Arizona, Colorado, Florida, Iowa, Michigan, Nevada, North Carolina, Pennsylvania, Virginia and Wisconsin.

The analysis compared voter registration data from election officials in each state from the beginning of 2015 through the end of the summer of 2016. (States report voter registration data at different times, but most started around Jan. 1, 2015 and ended around Sept. 1, 2016). USA TODAY then looked at the same time period in 2012.

USA TODAY also looked at voter registration data in the two states that provide detailed data on Hispanic voter registrations: Florida and North Carolina.

Mark Hugo Lopez, director of Hispanic research at the Pew Research Center, analyzed USA TODAY's findings and described them as a "good barometer we should be using" for measuring Hispanic voter registrations given the limited data available. He said some Hispanics are definitely registering specifically to oppose Trump, but the overall numbers show that Hispanic voting numbers would have risen with or without Trump as the Republican nominee.

"It looks like this year is no different in terms of the growth of the number of Hispanic registered voters," he said.

Here are some of the findings:

  • The 50 counties analyzed represent the fastest-growing portions of those states and are driving most of the voter registration increases. Voter rolls in the most heavily Hispanic counties grew faster than the state average in 9 out of 10 states, both in 2016 and 2012.
  • The voter registration increases in the most heavily Hispanic counties drove Democratic gains in most of the states, even if the states overall are trending Republican. In Iowa, Republicans have added 14,000 more registered voters than Democrats leading up to the election. But in the five counties examined, Democrats outgained Republicans 2-to-1.
  • In some cases, the state would have seen a decline in total voters from 2012 to 2016 if not for the heavily-Hispanic counties. In Wisconsin, the state would have lost 3,606 voters, if not for the increases in Milwaukee, Dane, Racine, Kenosha and Brown counties.
  • In some states, Hispanic voter growth has slowed. In North Carolina, Hispanic voter registration overall increased 23.3% during the 2016 election, compared to 25.2% in 2012.
  • Iowa was the only state during the 2016 election cycle to lose both voters across the state and in the counties with the most Hispanics.
  • The states with the largest voter increases in the most heavily-Hispanic counties were Florida, Arizona, Pennsylvania, Nevada and North Carolina.