Republican presidential front-runners Donald Trump and Ted Cruz have taken hardline stances on a range of issues concerning Muslims, and it could come back to bite them if either becomes the nominee.

That’s because civil rights groups have set a target of registering one million new Muslim voters for the coming elections, according to the New York Times. And advocacy groups believe this goal isn’t out of reach in a climate where Trump and Cruz have been accused of stirring anti-Muslim sentiment.

“The fear and apprehension in the American Muslim community has never been at this level,” Ibrahim Hooper, a spokesman for the Council on American-Islamic Relations, told the Times. “The anti-Islamic tidal wave is spurring civic participation.”

Groups like CAIR and the Islamic Circle of North America are working with mosques to turn the religious places of worship into registration centers, the Times reported. Registration drives are expected to be at its peak during the holy fasting period of Ramadan in June, when attendance at Islamic centers will be high.

A recent Pew Research Center study estimated that there are around 3.3 million Muslims in the U.S. currently, which is around 1% of the total population. That number is expected to double by 2050.

Most of the fear has been attributed to Trump, who has advocated for a complete shutdown of Muslims coming into the U.S., and has remarked in a recent CNN interview that “Islam hates us.” Cruz recently called for heightened patrolling of Muslim neighborhoods and refused to disavow the anti-Muslim views of his adviser.

Already, the relationship between Republicans and those practicing Islam are tenuous at best. A Pew Research study found that just 11% of American Muslims considered themselves Republicans, compared to 70% who called themselves Democrats. The feeling is mutual—a separate Pew Research study found that Republicans felt the most negative towards Muslims compared to any other religious group, and even slightly below atheists.