MIAMI — Tasked with helping Republicans capture the Senate majority in November, Sen. Rick Scott handed Democrats an economic hammer to swing at his party this week with a plan that called for a tax increase on millions of Americans. While most of Scott’s plan to “Rescue America” focuses on cultural battles about gender, race and education, a line in the economic section proposing a tax hike on low-income earners offered a new line of attack for Democrats. After months of grappling with the political fallout from rising prices due to inflation, President Joe Biden’s team and other Democrats we…