For the second time in as many years, immigration has fizzled as a wedge issue at the polls. In 2006, Republicans hoped to use anger over illegal immigration to maintain control of Congress, but failed miserably, losing races even in states like Arizona and Colorado that have experienced large influxes of illegal aliens.

This year, Virginia Republicans tried the same maneuver in state races, with the same results. The Virginia GOP lost control of the state Senate in Tuesday's election, with Democrats winning four additional seats in the Senate and netting an additional three in the House of Delegates, despite efforts to rile up voters on the illegal immigration front. In both cases, other issues dominated the election, and there simply weren't enough voters for whom immigration was the No. 1 issue to roll back an increasingly Democratic electoral tide.

Virginia is a particularly interesting case study. Demographics in the state have changed dramatically in the last 10 years, including large influxes of immigrants both legal and illegal. Northern Virginia, which includes the suburbs bordering Washington, D.C., is trending more and more Democratic, tipping the partisan balance in the state.

In Loudoun County where I live, growth has been explosive. As home prices in the Washington area skyrocketed, young families found the only affordable alternative was to move farther out, in some cases 50 or 60 miles from Washington to what was, less than a decade ago, rolling hillside and farm land.

The newcomers tended to be more moderate than hardcore conservative. As a result, a county that was once a reliable Republican bastion ousted four out of six incumbent Republicans on its nine-member governing board of supervisors on Tuesday. The big issue wasn't immigration but whether GOP supervisors were simply handmaidens of developers, who were building homes far faster than the county's infrastructure could support.

Immigration was a non-starter in Loudoun, despite an earlier move by the GOP-controlled board to pass a resolution aimed at illegal aliens. And while the sponsor of the resolution retained his seat, he won by barely 200 votes with very low turnout, despite spending more money than any other candidate for the board of supervisors.

The one race in the county where a challenger tried to make illegal immigration the big issue was for county sheriff. The incumbent, who had run in the past as a Republican, failed to get an endorsement from the state party this time because he was viewed as insufficiently tough on illegal aliens, forcing him to run as an Independent. His Republican challenger harped continuously on the illegal immigrant threat, but apparently few people cared.

The Republican came in third, behind both the Democratic candidate and the now Independent incumbent. It didn't help matters that the Republican admitted that as deputy sheriff he routinely fixed friends' speeding tickets, leading at least this Loudoun voter to wonder: What part of illegal didn't he understand?

Even in Prince William County, which gained national attention this summer for passing one of the toughest local anti-illegal alien measures in the country, immigration wasn't decisive. Two of the most outspoken anti-illegal members of the board of supervisors won re-election, but so did the incumbent Democratic state senator in the race, whom his opponent had tried to paint as soft on illegal immigration.

What the Virginia GOP failed to appreciate on the illegal immigration front is the difference between intensity and salience in voter behavior. Some voters are intensely angry about illegal immigration, and they tend to dominate the talk show airwaves and show up at candidate gatherings. But the number of voters for whom this is the single biggest voting issue is relatively small.

A larger group of voters may worry about the effect of illegal immigration on their communities; but when they go to the polls, other concerns trump the issue. Illegal immigration simply isn't a salient issue with most voters on Election Day.

The GOP's tough stand on immigration is a big loser with Hispanic voters, who are becoming a larger share of the electorate and whom the party had courted of late. Illegal alien bashing also appears not to have the broad appeal to other voters that some Republican strategists thought it would. If they're smart, Republican candidates will find a new issue to tie their hopes to next year.