BOSTON -- Former Massachusetts Gov. Mitt Romney is stepping back into the public spotlight after spending two years behind the scenes laying the groundwork for a second presidential campaign. (snip) Romney has shifted from social issues that brought accusations of flip-flopping and undermined his 2008 White House bid. With unemployment hovering around 10 percent, his new focus is on economic themes and fix-it skills he claims as a former businessman. That plays to what some observers believe would be his strength in a second race. They could also distinguish him from potential rivals such as former Alaska Gov. Sarah Palin,...