WASHINGTON — The Supreme Court announced on Monday that it would consider whether partisan gerrymandering can violate the Constitution. The case could reshape American politics.

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The new standard proposed by the challengers tries to measure the level of partisan politics in legislative maps by counting “wasted votes” that result from the two basic ways of injecting partisan politics into drawing legislative maps: packing and cracking.

Packing a lot of Democrats into a single district, for instance, wastes every Democratic vote beyond the bare majority needed to elect a Democratic candidate. Cracking, or spreading, Democratic voters across districts in which Republicans have small majorities wastes all of the Democratic votes when the Republican candidate wins.

In a 2015 article, Nicholas O. Stephanopoulos, a law professor at the University of Chicago and a lawyer for the plaintiffs, and Eric McGhee devised a formula to measure partisanship. The difference between the two parties’ wasted votes, divided by the total number of votes cast, yields an efficiency gap, they wrote.

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