The hard-line immigration policies of President Donald Trump could be a significant barrier to Republican electoral success with the largest and most diverse generation in American history, according to Stella Rouse, associate professor of government and politics and director for the Center for American Politics and Citizenship.

Rouse, who co-authored the recently published book ’The Politics of Millennials," wrote in a Washington Post op-ed yesterday that millennial voting preferences and positive views of immigration could be a big factor in who wins future elections:

In the run-up to the 2018 midterm elections, President Trump doubled down on the restrictive immigration positions that fueled his 2016 presidential campaign. The last few weeks of the campaign, he repeatedly warned Americans about the migrant caravan headed to the United States from Central America, and advocated for the repeal of birthright citizenship. Trump hoped to mobilize Republican voters, thereby helping to elect Republican candidates. Especially in the Senate, this may have helped Republicans gain two seats.

But in the long term, Trump’s anti-immigration approach may alienate millennial voters — and backfire on the Republican Party. The millennial generation, born between 1980 and 1997, is the largest and most diverse adult cohort.

Read more in The Washington Post.