Liberals and other observers today have been running with an easy story line — that a new USA Today/Gallup swing states poll showing a large gender gap in the presidential race — confirms that Republicans have really damaged themselves with women thanks to GOP stances on contraception, abortion and other issues. That’s possible, but I’d urge caution for a few reasons.

First, it’s never a good idea to put very much weight on a single poll, but it’s especially risky to trust the subsets of voters in a single poll. Remember, relatively large swings that are really just statistical noise are very possible in national polls — and the smaller the subset of voters surveyed, the larger the chances for meaningless patterns to appear.

Second, at least some of the changes in this poll — assuming they are real — could be the effects of recent heavy news coverage of the issues which typically might induce a gender gap. And yet there’s no way of knowing whether those same issues will be on voters’ minds in October and November. Certainly, Barack Obama’s campaign might be tempted to focus attention on issues which play badly with women, so it’s worth paying some attention to these numbers, but Obama can’t count on Republicans to play along as well as they’ve done for the last few weeks.

And, third, it’s always difficult to connect specific campaign incidents and issue positions to horse race polling results. David Frum is correct that a long-term gender gap can’t be traced to what Rush Limbaugh said recently, and it doesn’t appear to be simply a direct policy effect caused by abortion.

None of this is to say that everyone should just ignore this new poll. Just that the best way to approach these numbers is with quite a lot of caution.