Every few years America’s major political parties get very interested in getting people registered to vote – or maybe more accurately, in getting the “right” people registered to vote.

It’s a lot easier to come up with a winning hand on Election Day when the deck is stacked in your favor. So, for months now, supporters of President Barack Obama and Republican presidential nominee Mitt Romney have been knocking on doors and standing corners trying to register like-minded people. In a close election every vote may count, particularly in the swing states.

To get an idea of who’s ahead in the registration game, Politics Counts looked at the tallies in key states where voters register as Democrats or Republicans – Colorado, Iowa, Florida, Nevada, North Carolina and Pennsylvania. We then compared those figures to previous voter registration counts in 2008 and 2004.

Who’s winning? That depends on the state you look at and the comparison point you choose. Both sides can point to some numbers in their favor. But when you step back and look at the numbers in fuller context, the real question may be how much those Democratic and Republican registrations will really matter.

The Obama team is up in registrations in key states, as they noted this week, but overall it could be argued Obama is having a bit of a down year. The percentage of voters registered as Democrats in every one of these states is lower than it was in 2008.  And there were drops of two percentage points or greater in Florida, Iowa and North Carolina.

That said, 2012 has not been a gangbusters year for the GOP either. The percentage of Republican registrations is up in one state compared to 2008 – Iowa – slightly down in three others – Colorado, Nevada and North Carolina – and they are flat Pennsylvania and Florida.

On the whole, however, when you look at all the current numbers, as a measure of enthusiasm or interest, compared to 2008 they would seem to indicate: advantage GOP.

Using the 2008 election as a measuring stick is problematic, though. It was not a normal race. There was big enthusiasm on both sides of the aisle. Voter registration counts were up in most states across the country – in some cases sharply. And remember Mr. Obama won that race comfortably, by seven percentage points and nearly 200 electoral votes. For the rest of this Politics Counts column, please visit the Wall Street Journal's website.