The son and namesake of late Philippine dictator Ferdinand Marcos strengthened his lead over his closest rival ahead of the presidential election in May, results of a new poll released on Sunday showed.Ferdinand Marcos Jnr garnered a 44-point lead over Philippine Vice-President Leni Robredo in the January 19-24 survey by independent pollster Pulse Asia, an 11-point increase compared with the previous poll in early December.A total of 2,400 respondents were asked to pick their first choice for…