Things appear to be tightening in Maryland, where a poll leaked to The Daily Caller shows the gubernatorial race is “extremely close — only 2 points, 46 to 44, separate Democratic Lieutenant Governor Anthony Brown and Republican small businessman Larry Hogan.”

One should always be cognizant of outliers — and it’s worth noting that this survey was commissioned by the Maryland Republican Party. It’s also true that polls conducted by Gonzales this cycle have tended to show the race tighter than others — but as the Washington Post noted, Gonzales “does not have a partisan track record.”

With those caveats out of the way, let’s assume for a minute this survey is accurate. This would represent a nine point swing from a week ago, when, according to the RealClearPolitics poll average, Hogan was down by 11 points.

How could this be possible? I mean, what has happened in the last week? For one thing, President Obama — not welcome on the trail in red states — campaigned for Brown in Maryland, where crowds began streaming out during his speech, leaving empty bleachers behind.

Could it be that President Obama is such a drag on Democrats that he even hurts them in … Maryland? That’s one possibility. Another factor: New Jersey Governor Chris Christie, the head of the Republican Governor’s Association, has also been stumping hard for him.

Whether or not these events represent causation or correlation, is unclear. But it seems unlikely that Gov. Christie would be visiting Maryland so often — so late — unless there were a reason.