President-elect Donald Trump and his allies prepared Wednesday to take power after a decisive election victory that could hand Republicans unified control of government and give Trump a broad mandate to pursue an agenda of radical change.

Vice President Kamala Harris called Trump to concede and then addressed supporters in the afternoon, saying she told Trump she would help with his transition and “engage in a peaceful transfer of power.” Republicans have clinched the Senate majority; the race for House control is still unsettled, but the GOP is on track to retaining control.