U.S. Republican presidential candidate Mitt Romney appears ready to add to his lead Tuesday to become the party's nominee and run against President Barack Obama in November's election.
Three primaries take place Tuesday, including one in the nation's capital. The others are in the eastern state of Maryland and the northern state of Wisconsin.
Romney, who is the favorite in all three primaries, could pass the halfway mark in securing the number of delegates needed to clinch the nomination. He spent much of Monday criticizing Obama and Democrats for their economic policies, rather than talking about his Republican opponents.
The main contender against the former governor of Massachusetts is Rick Santorum - a former U.S. senator from Pennsylvania. His state is one of several that will hold the next round of primaries in three weeks. Santorum says he is determined to stay in the race, despite Romney's sizable lead.
Former House of Representatives speaker Newt Gingrich and Texas Congressman Ron Paul are far behind in the race for the Republican nomination.
If no candidate secures the necessary number of delegates before the Republican convention in August, the party's nominee would be decided at the convention.
