DeRemer, a former Republican member of Congress from Oregon, is scheduled to appear before the Senate Committee on Health, Education, Labor & Pensions, the first stop in her confirmation process.

The Senate confirmation hearing for President Donald Trump’s pick for labor secretary offers a critical test for the Republican Party over the populist wave that helped Trump win over many working-class households.

WASHINGTON—Republicans, long skeptical of unions and labor regulations, have lately shown signs of openness toward both. A confirmation hearing Wednesday for President Trump’s pick to run the Labor Department provided little evidence that they’re ready to translate that into policy.