litmus test

While campaigning against Clinton, Trump had positioned his victory as a litmus test for democracy.

Support of abortion bans as a litmus test for GOP politicians took some time to reach its full flowering.

This isn’t to say playing me bowling well is a litmus test for being a good batter, far from it.

Where Schiff and Garvey stand on the Republican, who is again running for president, has repeatedly been used — including by the two campaigns — as a litmus test for their politics.

Still, the poll results will be seen as a litmus test ahead of Germany's federal elections in 2025.