As currently written, the law effectively gives presidents carte blanche to impose tariffs for reasons of “national security”—even if the security angle is extremely tenuous. It’s a loophole Trump has exploited, and some Republicans are privately worried that a future Democratic administration could follow in his footsteps and declare that tariffs are necessary to combat, say, global warming.

Toomey’s bill would limit the definition of “national security” in the law, and it would require the Pentagon to sign off on the declaration—as opposed to the Commerce Department, which handles it now. Congress would have 60 days to review and vote on any proposed Section 232 tariffs.

The other bill is Trade Security Act, sponsored by Sens. Rob Portman (R–Ohio) and Doug Jones (D–Ala.). It too would transfer the Section 232 process from the Commerce Department to the Pentagon, and it would add a mechanism to allow Congress to block presidential tariff declarations. The Portman/Jones bill would require Congress to pass a resolution disapproving of a tariff in order to revoke it, while Toomey’s bill would require congressional assent before tariffs could be imposed—essentially forcing Congress to be part of the discussion, and removing the possibility that a do-nothing Congress would allow a president to act unilaterally.