Half a mile east of the U.S. Capitol stands a handsome three-story townhouse with red-brick siding, copper oriel windows, and a corner entrance inscribed with the name of its owner, the innocuous-sounding Conservative Partnership Institute. Most passersby likely have no idea that Donald Trump’s campaign to overturn the 2020 presidential election was largely coordinated behind these stately walls. So was the January 6 rally that turned into a violent assault on the Capitol. In recent years the CPI has spent tens of millions of dollars recruiting and training operatives to staff what its leaders hope will be a second Trump administration. If the Heritage Foundation’s Project 2025 provides the battle plan, the CPI represents the staging ground.Late on a balmy night this summer, though, the…