CNN says Ron Kirk has the buzz, though they say his campaign is the hare to John Cornyn's tortoise:

At a recent fund-raiser in the affluent Dallas neighborhood of Highland Park, Kirk worked the crowd of mostly wealthy, white Republicans with a master's touch. His smile beamed; he seemed to know everyone and was in a constant motion of handshaking and backslaps.

When he was Dallas mayor, Kirk won firm support from these white Republicans who helped Bush when he was governor of Texas. And that is what has Republicans worried. "All the excitement is on the Kirk side of this election," said Cal Jillson, a professor of political science at Southern Methodist University in Dallas.

He said Cornyn was a solid candidate who was likely to win, but "none of the sizzle is on his side of the equation."

"This is one of the more high profile races in the country simply because there is a highly qualified black candidate who is within striking distance of winning this race," he said.