President Donald Trump rallied for Republican candidates in Ohio, expressing confidence that his party could outperform expectations in the November 3 midterm elections.

Trump predicted a “big surprise” and urged Republicans to turn out to vote, saying the party would win despite polls showing Democrats gaining ground.

He campaigned for Republican Senate candidate Jon Husted and gubernatorial candidate Vivek Ramaswamy in closely watched Ohio races.

Trump also defended Ohio’s growing data-center industry and highlighted the economic benefits of the projects despite concerns about energy costs and their impact on local communities, Al-Jazeera has reported.

The Ohio rally came as Republicans face a challenging midterm environment, with Trump’s approval ratings and economic concerns creating difficulties for GOP candidates in several competitive races.