Donald Trump's fourth scheduled stop in eight days in Wisconsin is a sign of his increased attention as Republicans fret about the former president's ability to match the Democrats' enthusiasm and turnout machine.

Two dozen Wisconsin Republicans, including former lawmakers, other former elected officials and a GOP sitting district attorney, have signed an open letter declaring their support for Democratic Vice President Kamala Harris in her campaign for president and condemning the Republican nominee former President Donald Trump.

Liz Cheney, the former Republican congresswoman from Wyoming, will appear with Vice President Kamala Harris at a rally in Wisconsin Thursday evening, as the vice president seeks to win over disaffected Republicans in the key battleground state.