ARI SHAPIRO, HOST:
Let's stay on Capitol Hill where some lawmakers worry President Trump could be starting a trade war. Some Senate Republicans are working on a plan to let Congress step in and limit what the president can do. As NPR's Kelsey Snell reports, even some of the president's allies fear that his aggressive trade actions could harm the economy and loyal Republican voters.
KELSEY SNELL, BYLINE: It isn't uncommon for some congressional Republicans to disagree with President Trump. But when it comes to a possible trade war with U.S. allies in Mexico, Canada and the European Union, Tennessee Republican Bob Corker says they need to put their frustration into legislation.
BOB CORKER: I've always expressed my disagreement when it's occurred. This one is one that we can deal with legislatively. And I also know that the vast majority of our caucus would agree with this.
SNELL: Corker is leading a group that wants to limit Trump's ability to invoke national security to levy higher taxes on foreign imports. That is how Trump explained those recent steel and aluminum tariffs on U.S. allies. Corker is working with a group of Republicans and a handful of Democrats on a plan that he says will allow Congress to review and approve tariffs that are based on national security. Corker says the plan isn't finished, but trade authority was given to Congress in the Constitution. And over time, the power has shifted to the White House. Iowa Republican Chuck Grassley hasn't signed on to Corker's plan, but he says he worries that tariffs and Trump's threat to pull out of the North American Free Trade Agreement will harm farmers in particular.
CHUCK GRASSLEY: And from the standpoint of agriculture, what can happen if the president fails - yes I'm very nervous myself. And in 12 town meetings last week in northwest Iowa, that's what I constantly heard.
SNELL: Senate Majority Leader Mitch McConnell wouldn't take sides Tuesday, but a growing number of Republicans say they understand Corker's plan. Colorado Republican Cory Gardner runs the Republican Senate Campaign Committee. He hasn't decided if he'll back the Corker plan, but he says tariffs could be bad politics for Republicans in the midterm election.
CORY GARDNER: I just think a growing economy is going to be critically important in November. And if tariffs are taking away from that, then that's certainly something that would not be helpful.
SNELL: Corker wants to move quickly and attach the proposal to the usually bipartisan annual defense bill. But not every Republican who worries about the tariffs is willing to back the longshot plan. Louisiana Senator John Kennedy says he's still willing to give the president the benefit of the doubt.
JOHN KENNEDY: We're not there confronting the president on tariffs. I still believe that the president is using the tariffs as a bargaining chip. I still believe he is way too intelligent to get us into a trade war. You can't win a trade war. The only way to win it is not to fight.
SNELL: And there are other challenges to convincing Republicans to sign on. Corker wants to make the amendment retroactive for two years so that Congress can review the controversial tariffs Trump has already announced, but that might not be constitutional. The plan is gaining momentum even among some Trump allies like South Dakota Senator Mike Rounds.
MIKE ROUNDS: It's not that we don't want fair trade. We want fair trade just like the president does. But we want to know what his endgame is.
SNELL: Even with that growing support, Corker knows it won't be easy to force the president to give up some power on trade.
CORKER: Doing anything around here like pushing a major boulder uphill. So we'll see.
SNELL: Corker only has a few days to make his case. Kelsey Snell, NPR News, the Capitol. Transcript provided by NPR, Copyright NPR.