COLUMBIA, S.C. -- Absentee ballots were pouring in at a rapid pace in South Carolina, setting the stage for what could be a possible record turnout for Saturday's Republican presidential primary.

Sen. John McCain of Arizona is looking for a heavy turnout of crossover voters to defeat Gov. George W. Bush of Texas, favorite of the GOP establishment.

Some of the heaviest absentee balloting was in upstate South Carolina, a traditionally Republican area where Bush would be expected to be strong. Counties that tend to vote Democratic -- important for McCain who seeks backing from independents and crossover Democrats -- also saw heavier than normal early balloting.

State Republican officials predicted voter turnout would be well over 300,000 voters, compared with more than 276,000 the last time.

Both campaigns were reaching out to core voters, including taped phone messages from leading state Republicans to possible Bush voters, and a mass-mailing of postcards, including about 65,000 to veterans.

Scattered showers and temperatures in the 60s and 70s were in the forecast for Saturday.