In both states the Republicans campaigned for lower spending and taxes, in contrast to the Obama Democrats' policies. Heavily Democratic New Jersey voted narrowly for Republican Chris Christie, and in Virginia, the state voting closest to the national average in 2008 and 2012, Republican Bob McDonnell won a landslide victory.
This turned out to be a good predictor of 2010, when Republicans captured 63 seats and control of the House of Representatives, plus a bunch of governorships and some 600 state legislative seats.
Similarly, Democratic victories in those two states in 2005 turned out to be a good predictor of Democrats' big gains in 2006 and 2008.
The Republicans' good year in 2009 was not as good a predictor of 2012, when Barack Obama won re-election. But he had to fight for it, and he was the first Democratic president re-elected with a reduced percentage of the vote.
But sometimes off-year elections turn out to have little precedental value. That seems to be the case this year.
In New Jersey, Chris Christie seems headed to a landslide re-election victory -- the first in that state since Tom Kean won a second term in 1985. His lead in the realclearpolitics.com average of recent polls stands at 59 to 28 percent.
The tough-talking Christie was already strong before Hurricane Sandy hit last November. He managed to pass legislation cutting back on public employee unions by getting the support of Democratic legislators with backgrounds in private-sector unions.
But his performance during Sandy made him a rock star with New Jersey voters. A big Christie victory could make Christie a strong presidential candidate in 2016. But it won't say much about the standing of Republicans or Democrats nationally.
The situation is different in Virginia. Current polling shows a tie, with 40 percent for former Democratic National Committee Chairman Terry McAuliffe and 39 percent for Republican Attorney General Ken Cuccinelli.
Their stands on issues can be seen as roughly congruent with their national parties. But the election may hinge on other things. Each candidate has liabilities that make him arguably unelectable.
McAuliffe has had little involvement in Virginia state politics, except for a failed primary campaign for governor four years ago.
And his business background, which he has said will help him spur the state's economy, also has some problems. He started a firm called GreenTech, which was supposed to produce environment-friendly cars in Virginia.
Instead it built a plant in Mississippi (which it won't let reporters see), has hired only about 100 people and has produced a few hundred golf-cart-sized vehicles.
Two federal investigations are looking into the firm's financing through a program that lets rich foreign investors get visas. McAuliffe recently revealed that he resigned as CEO last December, but he's still the largest stockholder.
As for Cuccinelli, he has been in the habit of making provocative statements taking conservative stands on cultural issues.
Some of his moves have been popular, like his early lawsuit challenging Obamacare on constitutional grounds. His efforts to track down DNA evidence to absolve those wrongfully convicted of crime should be attractive to voters of all stripes.
But his strong stands on abortion could antagonize many voters in a state that has voted for the pro-abortion-rights presidential candidate in the last two elections. And he has accepted gifts from the Star Scientific CEO who lavished them on incumbent McDonnell and his family.
Both of the 2013 candidates have assets, as well. I find both of them likeable characters, though many voters may not.
Both are articulate and have lots of energy. McAuliffe is a great fundraiser, and Cuccinelli has shown he can win in the Democratic-trending Northern Virginia suburbs.
Overall this race seems likely to hinge more on personal factors than on issue stands. If so, it won't tell us much about national trends.
(Daily Corinthian columnist Michael Barone, senior political analyst for The Washington Examiner, is a resident fellow at the American Enterprise Institute, a Fox News Channel contributor and a co-author of The Almanac of American Politics.)