Mitt Romney yesterday said that he has been paying close to 15 percent on his income taxes in recent years, a rate that is lower than many Americans pay and one that fueled further attempts from his Republican rivals to cast the former Massachusetts governor - and wealthiest candidate in the race - as out of touch. With just four days left before the primaries in South Carolina Romney continued to face scrutiny for his wealth, how he earned it, and how he now talks about it. Newt Gingrich called his explanation “nonsensical’’ for not releasing his tax returns until April at the earliest. Rick Perry called on Romney to release all tax returns going back at least six years - not just the most recent year.