BLACKSBURG, Va. -- Democrat Tim Kaine and Republican George Allen left Virginians sure of two things Thursday in their final U.S. Senate debate: Voters face two very distinct choices on Nov. 6, and the candidates' race will be a bitter fight to the very end.

Less than three weeks from Election Day, Kaine used the showdown at Virginia Tech to appeal to moderates tired of a gridlocked Washington, while Allen tossed red meat to his conservative base by linking his Democratic rival to the Obama administration.

Allen immediately went after Kaine as "President Obama's senator." It's a message that Allen shied away from when Obama's popularity was higher in Virginia but that he's resurrected now that Republican presidential nominee Mitt Romney has drawn even with Obama in the polls.

"In Washington, you deserve a strong independent voice," Allen said. "Not an echo."

Kaine, meanwhile, portrayed himself as being above the partisan fray in Congress while painting Allen as an ideologue who would prolong the gridlock. Kaine called Republican President George W. Bush "a partner" who worked with Kaine to make the Dulles Metrorail project a reality, even as he derided then-Sen. Allen for voting in lockstep with Bush 96 percent of the time.

"This is a huge difference between the two of us," Kaine said. "I do not think it is anti-Virginian to support the president of the United States."

Throughout the hourlong exchange, Allen and Kaine differentiated themselves on the economy and taxes. Allen accused Kaine of always wanting to raise taxes. Kaine said Allen's plan to cut the deficit would reward the rich and slash programs that benefit the poor.

Kaine vowed to fight pending defense cuts that Allen claimed his rival supports. And Allen pledged to preserve Social Security despite Kaine's claims that he would gut it.

Both candidates were looking for a breakthrough moment in the debate, a chance to finally pull ahead of the competition in a race that could decide which party ends up controlling the Senate.

At times, the exchange between the two former governors sounded very much like the presidential race, with Kaine charging that Bush-era policies created the current financial crisis and Allen blaming Obama for the slow economic recovery.

"You were governor during the Clinton boom years, the biggest expansion of the American economy since World War II," Kaine said. "And I was governor during the deepest recession since the 1930s, a recession that was largely promoted by policies you voted for in the Senate."

Facing voters in the conservative southwest corner of the state, Kaine avoided challenging Allen on the women's health issues that took center stage in Northern Virginia. Allen, meanwhile, took advantage of the region's conservative leanings to assail Kaine as a tax-and-spend liberal.