GOP, Dems battle over Trump's SAVE Act. But who will it really help?

The president says the election security bill 'will guarantee the midterms' for Republicans. Available data is far less clear cut. Here's why.

WASHINGTON –  As President Donald Trump has pushed congressional Republicans to pass stiff new voter registration requirements, he has argued that the legislation will benefit their party in the upcoming election.   

“It will guarantee the midterms,” Trump told Republican lawmakers gathered March 9 at his Doral, Fla. golf resort, in urging them to make it their No. 1 priority. “If you don’t get it, big trouble, my opinion.”

The fact that Republicans have been so gung-ho for the bill, known informally as the SAVE Act, suggests they do believe their party would benefit in a year when forecasters project they may lose control of the House of Representatives.

Meanwhile Democrats uniformly oppose the Safeguard American Voter Eligibility Act, and voting rights and civil rights advocates worry that it would disenfranchise many voters who lack access to proof of citizenship − a risk that is usually considered a threat to Democrats, whose supporters are disproportionately young, nonwhite and low-income.

But would the SAVE Act actually give Republicans a partisan advantage? The evidence is unclear.