Primaries are held in two southern states of the United States on Tuesday, is the Alabama and Mississippi. Meanwhile, the caucuses were held in Samoa and Hawaii.
At the end of the day, 107 delegates will be appointed to the party convention.
In the southern states, Mitt Romney, trying to solidify his support, faces difficult challenges facing his rivals Rick Santorum and Newt Gingrich.
This close contest to three offers to former Massachusetts Governor Mitt Romney, a key opportunity in a region that has been slow to support it.
These primers may also help make a final verdict on the candidature of Mr. Gingrich, who is well entrenched in the south.
The showdown in southern Republican unfolds as we see a sharp recent decline in approval ratings of President Barack Obama in the context of rising gasoline prices and turmoil in the Middle East.
A poll Washington Post-ABC News found that 46 percent of those polled approved of how the president is doing its job, while 50 percent disapproved.
Another poll conducted for The New York Times and CBS showed an approval rating of 41 percent, against 47 percent disapproval.