Senate race? What Senate race? Why Virginians pay a big race little heed.

Despite an avalanche of advertisements and the two Senate candidates' long legacies in Virginia politics, Republican George Allen and Democrat Tim Kaine have an unexpected challenge in their tight race: getting voters to pay attention to them.

“I am shocked, as I’m going out and ringing [on] doors [on behalf of GOP candidates], people don’t know the Senate candidates, despite their pedigree,” says former Rep. Tom Davis (R), who represented a district abutting Washington, D.C., for a dozen years until 2008.

The Senate rivals have now debated in public five times, most recently Thursday night. Millions have been spent by their campaigns to reach voters. Yet local politicos report that many Virginians seem to have not the foggiest idea what is going on in one of 2012’s marquee Senate races.

Susan Allen, campaigning for her husband, recently wrangled a light moment out of voter ignorance. She had run through her stump speech and was ready for questions from a handful of employees at a small medical company in Mt. Jackson, Va., a town in the commonwealth’s Shenandoah Valley.

The first questioner asked about the main differences between her husband, who has served the state as both a governor and a US senator, and his opponent, also an ex-governor.

As Mrs. Allen began her explanation, the questioner broke in again. “What’s his name, by the way?” he said, referring to Mr. Allen’s opponent.

“Tim Kaine,” she whispered, to a laugh.

What gives? There are a couple of theories.

One is that time in the commonwealth is measured in “Virginia years,” as Mr. Davis put it. The state is changing rapidly as its minority representation grows, and in the suburbs around Washington, D.C., there's a high churn rate of people moving in and out. As a result, a fair share of the voters who elected Allen (who ran for governor in 1993 and Senate in 2000) and Kaine (who ran for governor in 2005) simply aren't around anymore.

In 2000, less than 5 percent of the state was Hispanic. In the 2010 census, that figure grew to more than 8 percent. Virginia is about two percentage points more Asian in 2012, at about 6 percent, than in 2000.

Another is that the state is awash in political advertising – and the Senate candidates may be tuned out as “just another political ad.”

In 2008, nearly 59,000 presidential ads were aired across the commonwealth, according to data from CNN and Campaign Media Analysis Group. The Obama and Romney campaigns had roared past that mark by Sept. 30, with more than 80,000 aired, according to the Wesleyan Media Project.

Compare that with the Senate campaigns, which aired nearly 22,000 commercials combined through the end of September, according to data from the Wesleyan Media Project.

Some voters may be turned off by the negative tone of many ads in both the presidential and Senate campaigns, says Bob Denton, a professor of political communication at Virginia Tech in Blacksburg, Va.

Attack ads can activate a candidate's base and may hit home with a few voters leaning in one direction or another, he notes. But “there can be a backfire effect from the standpoint of cynicism, and the older people are the more sensitive they tend to be in terms of that cynical attitude,” Professor Denton says. Brutal negativity “could suppress votes if you’re not careful.”