Gabriella Hoffman’s paycheck is a little lighter today, thanks to a payroll tax increase that is forcing millions of Americans to make the kind of tough budget cuts their representatives in Washington lawmakers seem unwilling to tackle. Hoffman, a 21-year-old Virginian who works at a nonprofit, estimates her paycheck will be roughly $30 less this biweekly pay period, or about $780 annually, thanks to the end of a two-year cut on payroll taxes, which fund Social Security. The tax has risen back up to 6.2 percent from 4.2 percent, costing someone making $50,000 annually about $1,000 per year and a...