OLYMPIA — A sign should be plastered on the governor's race primary results saying: "View with caution."

Second-day returns show Democratic candidate Jay Inslee with about 47 percent of the vote and Republican Rob McKenna with almost 43 percent.

Inslee's campaign has argued primary voters are more conservative than those in the general election. McKenna's camp has said just the opposite.

The reality is, it's hard to say for sure. "It's the job of the campaigns to try to spin this, but they are just making stuff up," said Matt Barreto, a political-science professor at the University of Washington.

Barreto said research suggests primaries tend to bring out the party faithful for both sides. "It doesn't tend to tilt to one party or the other," he said.

An argument could be made that Democrats may be overrepresented in the primary, considering more Washington voters identify themselves as Democrats.

Surveys by Seattle pollster Stuart Elway shows Democrats make up roughly a third of the electorate while Republicans account for 25 to 27 percent of voters. Independents, the remainder, are the least likely to vote in a primary, Barreto said.

Elway, however, notes, "The biggest variable is age."

Around 60 percent of the people who've voted in all of the last four elections are over 60, he said.

While there's some speculation that older people tend to be more conservative, that's not necessarily the case in Washington, Elway said.

"In my last poll, McKenna was leading Inslee among voters under age 35," he said. "We keep looking for a key to unlock all this stuff and it is not there. There are way more variables than that."

Chris Vance, a former chairman of the state Republican Party, said he views the primary as a rough guide to which races are the most competitive in the state.

"When you look at the McKenna-Inslee race, these numbers just confirm what we knew: It's going to be competitive. It's going to be close," Vance said.

"I think if you look at the primary results, plus the last two polls, you have to come to the conclusion that McKenna has gone from being slightly ahead to slightly behind, but the race is really competitive."

Andrew Garber: 360-236-8266 or agarber@seattletimes.com