Polls opened Tuesday morning as Republicans cast their ballots for their party's presidential nominee in the largest day of state-by-state voting yet as candidates compete for the right to face Democratic incumbent Barack Obama in November's presidential elections, dpa reported. Ten US states as diverse as the southern state of Georgia, the industrial Midwestern state of Ohio and sparsely populated Alaska are to cast ballots on Super Tuesday, as the day has come to be known. The first polls opened at 6 am in Virginia (1100 GMT). The last votes will be cast in Alaskan caucuses that end at 8 pm (0500 GM Wednesday). Former Massachusetts governor Mitt Romney hopes to tighten his lead as Republican frontrunner, but must face three other candidates- former Pennsylvania senator Rick Santorum, former speaker of the House of Representatives Newt Gingrich and Texas Congressman Ron Paul- who are hoping to unseat him as the party's heir apparent and claim support from the party's conservative wing.
