In March, in the latest salvo, the Republican-controlled Senate passed a bill to authorize impeachment of justices if their decisions “usurp” the power of other branches. But the climactic battle is expected in the November elections, when conservatives hope to remake the seven-member Supreme Court in a flash, by unseating four justices regarded as moderate or liberal.

Partisan conflict over courts has erupted in many of the 38 states where justices are either directly elected or, as in Kansas, face periodic retention elections, without an opposing candidate. As conservatives in Washington try to preserve a majority on the federal Supreme Court, politically ascendant conservatives in several states are seeking to reshape courts that they consider to be overly liberal vestiges of eras past.

“We’ve seen this tug of war between courts and political branches all around the country,” said Alicia Bannon, a senior counsel at the Brennan Center for Justice at New York University.

Television spending in the election of two justices in Arkansas on March 1 reached $1.2 million, and candidates attacked as being too cozy with trial lawyers were defeated there, in part with money from outside business interests.

In Wisconsin, where a court seat will be filled in an election on April 5, ads sponsored by out-of-state groups from the left and the right have helped push total campaign spending to more than $2.6 million, according to data gathered by the Brennan Center and Justice at Stake, a nonprofit group in Washington that promotes judicial integrity.