Republicans took over from Democrats the seat in the key battleground state of South Carolinain the Senate races Tuesday, making it even harder the uphill fight by Democrats for the Senate control.

Exit polls also reported continued Republican control in two other key states of Kentucky and Oklahoma.

Earlier projected results said Republicans also defeated Democrats in Georgia, Ohio, Missouri, New Hampshire and Alabama, while Democrats registered victory in Vermont, Indiana, Connecticut, Illinois and Maryland.

The two sides swapped seats in Illinois and Georgia. In Illinois, Democrat Barack Obama pocketed the Senate seat held by aretiring Republican. He will be the only black member of the Senate.

Democratic Leader Tom Daschle faced a strong challenge in South Dakota.

In the races, 34 of the 100 seats in the Senate are at stake, 19 held by Republicans and 15 by Democrats. Currently, Republicansenjoy a majority with 51 seats, with 48 of the rest going to Democrats and one to independents.

Most of the incumbents are expected to be secured for reelection. Contests are considered competitive in five pro-Republican states of South Dakota, North Carolina, South Carolina,Louisiana and Florida, where retirements by Democrats gave chancesto Republicans to regain control. In the other battleground states of Alaska, Colorado, Kentucky and Oklahoma, the situation was believed to be in favor of Democratic challengers, who, however, have lost two of them.