As California goes, so goes the nation?

Busby versus Bilbray, check it out. By this time tomorrow morning, we may finally have some raw evidence of the national political mood, some insight into whether the Democrats really do have a realistic shot at taking over the U.S. House of Representatives in November.

Today, in the affluent, heavily-Republican congressional district that covers the north side of San Diego and neighboring La Jolla, a special election will be held to fill the seat vacated by convicted bribe-taker Duke Cunningham, a Republican who now wears prison garb. The Republican candidate today is Brian Bilbray; the Democratic candidate is Francine Busby. In a normal year, in this district, somebody like Bilbray (an ex-congressman himself, from a nearby district) would win in a walk. Yet the final polls are showing a statistical tie.

And that fact alone is worrisome for the national GOP, which has pumped more than $5 million into a race that should normally require very little outside money. This is a district where 44 percent of the registered voters are Republican, and only 30 percent are Democrats. The fact that Democrat Busby, a local school board member, is totally competitive on election eve would appear to confirm the warnings of Republican strategists that their party may be facing a tough political climate this year. As California political analyst Gary Jacobson put it the other day, "It's a district Republicans should never lose."

Stu Rothenberg, who runs the nonpartisan Rothenberg Political Report in Washington, put it best the other day. He wrote (in the subscription-only Roll Call newspaper) that the election tonight is "a test of Democratic efforts to ride a wave of voter dissatisfaction, and of Republican efforts to energize the party's conservative base."

If the GOP does lose tonight, the political impact would be felt nationwide. Democrats would claim bragging rights tomorrow, and declare that, as California-50 goes, so goes the nation in November. Whether that would be true, who knows. But, if Busby does win this district tonight, it would be a major story, for its rarity alone. Consider this statistic, courtesy of Jacobson: In California, since 1966, Democrats have lost every single congressional race in districts where registered Republicans have outnumbered registered Democrats by 3.7 percent or more; and as I noted above, the GOP advantage in this particular district is 14 percent.

But it's noteworthy that, even in this district, President Bush has not made an appearance on Bilbray's behalf. He has confined himself to leaving automated phone messages in the households of registered Republicans, praising Bilbray as "an ally in the war on terror." This is a testament to Bush's declining popularity, even in a district that he won in 2004 by 11 percentage points. Meanwhile, the national Democrats have countered with Al Gore, who has left his own phone messages on Busby's behalf, contending that "George Bush and the congressional Republicans have taken us in the wrong direction." (This is the same Al Gore who says that the political world is "toxic," and that he has no plans to get involved again.)

Both candidates have had their woes. Bilbray was embarrassed last week when John McCain abruptly canceled a fundraising appearance to boost the Bilbray candidacy, apparently because he and Bilbray strongly disagree on the immigration issue. McCain wants a "guest worker" program, while Bilbray is more outspoken about border enforcement. One might argue that maybe the McCain cancellation would help Bilbray with conservative voters in the district; the hitch is that another candidate on the ballot, independent William Griffith, is talking even tougher on immigration and boasts the endorsement of the San Diego branch of the border-patrolling Minutemen. Even if Griffith draws only a percent or two of the vote away from Bilbray, that could be crucial in a tight race.

Busby has been trying to tie Bilbray to the national anti-incumbent mood, and to the Democratic message about a GOP "culture of corruption." One Busby ad says: "Had enough? Corruption in Congress. High gas prices. No action on illegal immigration...It's time to fix our broken system, so Congress works for us again." On the other hand, Busby has been weathering her own problems. She has been targeted by the national conservative media for some ill-chosen words that she uttered last week at an Hispanic rally.

During this rally, an audience member told Busby, in Spanish: "I want to help (the campaign), but I don't have papers." The comment was translated. Busby gthen replied: "Everybody can help, yeah, absolutely, you can all help. You don't need papers for voting, you don't need to be a registered voter to help."

You don't need papers for voting...Somebody had taped Busby's comments, and the recording of that particular line quickly made the rounds. Within the past few days, it turned up on Rush Limbaugh's program, on the home page of The Drudge Report, and in a Republican party ad which suggested that Busby was encouraging illegals to vote.

Busby, whose previous experience as a major league candidate was the 2004 congressional race, in which she garnered 36 percent of the vote against Duke Cunningham, has sought to explain what she meant. The other day she issued a statement: "I was clarifying the question that was being asked in Spanish and then stated that you do not have to be a registered voter to help the campaign because there were so many people who appeared to be under 18 in the group who wanted to volunteer....I want to make it very clear that anyone here illegally does not have the right to be here, does not have the right to vote, does not have any right to be a part of the electoral process, and illegal people shouldn't be working on a campaign."

Maybe this episode won't matter; maybe the Democratic voters will simply be more energized than the more numerous Republican voters, and maybe the swing independents (22 percent of the district's electorate) won't care. But if Busby does lose this race by a hair, that parsed remark -- "You don't need papers for voting" -- will be remembered as her equivalent of John Kerry's "I voted for it, before I voted against it."

It could also be argued that a Busby loss would put the Democrats back at square one in the battle of 2006. But Stu Rothenberg, the Washington analyst, doesn't necessarily think so; he says it's important to remember the overwhelmingly Republican makeup of this particular district. Perceptions matter in politics, and he believes that, even in defeat, Busby could still give Democrats a PR victory: "A strong Busby showing (say, near 50 percent) would be evidence that the Democratic Deluge of '06 has begun."