The United States has experienced a surge in clean energy projects, representing more than $200 billion in new investments since President Biden signed an expansive climate bill into law more than a year ago. But the election and the potential for a Republican takeover is prompting concern that key parts of the law could be upended.

Former President Donald J. Trump, the front-runner for the Republican nomination, has repeatedly attacked central elements of the Inflation Reduction Act, including tax credits for purchasing electric vehicles. As a result, corporate executives have begun facing questions in recent weeks about the possibility that the legislation could be rolled back or changed in ways that could affect their clean energy investment decisions.

Republican lawmakers have tried, unsuccessfully, to repeal much of the law since it was passed entirely with Democratic votes in 2022. Company officials and energy researchers say a broad repeal of the law remains unlikely, given that many new projects are creating jobs and generating investment in Republican districts.

But a Republican administration would most likely try to influence the programs in other ways, such as through regulatory changes that would not require an act of Congress. That could have a significant impact on which companies and industries benefit from the programs and could impede achievement of the Biden administration’s climate goals.

“We’ve got to win the presidency and both houses” of Congress, said Representative Frank Pallone Jr., the top Democrat on the House Energy and Commerce Committee. “Otherwise it’s all going to be on the chopping block.”

The Inflation Reduction Act contains various tax credits and other subsidies to incentivize companies to deploy more clean energy projects. It also includes tax breaks for consumers to offset the cost of electric vehicles, heat pumps and other energy-efficient appliances.