Construction and factory workers, truck drivers, and cleaning crews don’t always have the flexibility to work a few extra years to beef up their monthly Social Security checks. Several blog readers stressed this point in their comments on a recent blog article, “Changing Social Security: Who’s Affected.” Lorraine Porto retired from a desk job, but her family is filled with craftsmen, carpenters, electricians, farmers, and truckers who worked “until they were worn out.” People in white-collar jobs don’t always appreciate “just how tough and demanding it is” to climb poles every day, descend into manholes, build skyscrapers, or bring in the hay in 90-degree heat and sub-zero temperatures, Porto said. Her comment was in response to the article, which described…