LAWRENCEVILLE, Ga. -- Republican Senate candidate David Perdue warned Saturday of a "closing window of opportunity" for Republicans to retake control of Congress.

"If we don't win the Senate in this cycle it could be 10 years going in this direction with Democratic leadership in the Senate and the White House. Guys, we cannot afford that," he told roughly 200 local Republican Party activists in a social hall next to train tracks in this small town.

And so Perdue concluded his 10-day, 65-stop statewide RV tour here Saturday morning by imploring Georgians to send him to Washington as a GOP counterweight to the final years of the Obama administration.

Capitalizing on the deep unpopularity of President Obama in the Peach State, Perdue has focused relentlessly on tying his Democratic opponent, Michelle Nunn, to Obama and by warning that congressional gridlock would likely fester under continued Democratic control of the Senate.

"We cannot let another 2012 happen at the national level," he said.

Wearing a distressed jean jacket with the collar popped, matching jeans and brown boots, Perdue looked much more at ease here than he has in other settings recently -- perhaps because polls in recent days show that his lead over Nunn is has widened slightly. But neither candidate appears to be earning the 50 percent needed to avoid a Jan. 6 runoff.

Perdue endeared himself to the crowd Saturday with stories from his travels around the state. At one stop Perdue said he had met a farmer, and when he started giving the farmer his pitch, the man stopped him and said: "I don't want to know what you're going to do for me, I just want you to stop doing things to me."

Then he quickly turned his attention back to Obama: "This president actually told us he was going to bring the country together. What did he do? He's been the most divisive president in our history, in my opinion," said Perdue.

Later, he added: "A vote for Michelle Nunn would be an proxy vote for Barack Obama," he warned. "With your help and God's will, we will not give Harry Reid and Barack Obama one more vote in the United States Senate." The crowd cheered in response.

Perdue and Nunn face each other again in their final debate on Sunday morning. Both candidates plan to hit the road again on Sunday and Monday, making one more quick tour around the state before ending up back in the Atlanta area on Monday night.