President Trump has changed course on Ukraine before. We all remember the Oval Office pyrotechnics (and the reconciliation). But his latest turn toward Russia could prove harder to reverse.

As Trump criticizes Volodymyr Zelensky, eases sanctions on Russia, and pursues a diesel deal with Vladimir Putin, Ukraine’s Republican supporters face a difficult choice: challenge the president or accept a policy they oppose.

Eurasia Group’s Clayton Allen explains why their leverage is limited, how the midterms could change the equation, and why even a Democratic victory wouldn’t guarantee a reversal.