(CNN) -- The Indianapolis Motor Speedway, home of the Indy 500, is one of the most famous racetracks in the world.
Hillary Clinton stops off at the Indianapolis Motor Speedway while campaigning in Indiana.
It's an enormous asphalt oval, a road that doesn't actually go anywhere.
The cars just go straight and turn left, go straight and turn left, for 500 miles; an experience that draws a quarter of a million die-hard race fans, but will exhaust the attention of most anyone else.
If the sun is hot and the beer is cold, you might even fall asleep. If you wake up an hour or two later, they'll still be racing.
Hillary Clinton campaigned there this week, which is entirely fitting.
U.S. politicians have learned an important lesson from motor sports and it's probably her only hope of winning the Democratic Party's presidential nomination: if you can stay in the race long enough, sometimes the car in the lead will crash.
Clinton and Barack Obama have been running in primaries and caucuses in U.S. states, territories and islands for five months now.
There have been more than 50 elections so far and they still aren't done. This week, the contests were in Indiana and North Carolina. Obama won North Carolina, the larger and more important of the two states, by a wide margin. Clinton won Indiana, but barely.
So Obama is still ahead in the number of delegates needed for the nomination.
For weeks now, Clinton's best hope has been for something bad to happen to Obama. She's kept the pressure on, with a campaign that is more and more confrontational.
His victory in North Carolina and the near-draw in Indiana suggest it hasn't worked. He's had his difficulties but he's still number one. And there are just six primaries and one month left.
So watch Obama drive conservatively and try to hold his lead. Watch Clinton hit the gas hard, bumping him and trying to pass at every opportunity.
Both of them do have enough time left to crash, but otherwise, they'll be going round and round a little bit longer, probably without changing places.