Donald Trump’s presidential campaign sent out a rallying cry to his base after President Joe Biden’s historic announcement Sunday — telling them that this could be the moment that returns Trump to the White House. “If we’re going to win back the White House, it will be all because of the momentum we build at this very moment — right here, right now!” his supporters were told in a fundraising email sent less than two hours after Biden dropped out. “Today we make history! Before this day is over, I’m calling on one million pro-Trump patriots to chip in and proudly say, “I stand with President Tr…