The primary election season began with amazing plot twists as candidates filed for office, thanks to Attorney General Lori Swanson's last-minute decision to jump into the race for governor, which lead to a dramatic game of political musical chairs among some of the DFL's most prominent figures.

With the primary just days away, the DFL race for governor is fluid. Swanson was hit last week with stories about former aides alleging she forced them to do political work, which she denied. But the campaign is clearly feeling the heat. They put up a 15-second TV ad hitting a rival, U.S. Rep. Tim Walz, for missed votes in Congress.

Tuesday's primary will be an interesting test of some hypotheses:

Can you win a DFL campaign with name recognition and some TV ads, as Swanson is attempting to do? The most well known among the DFL candidates, she's won statewide three times and has a well known running mate in U.S. Rep. Rick Nolan. She quickly raised and spent considerable sums on TV spots.

But politics has changed. Social media lets candidates reach voters directly where they are — and cheaply. Think of President Donald Trump's Twitter feed. Swanson entered the race without a social media presence.

Since about 2004, campaigns on both sides have also discovered that personalized messages from friends, family and neighbors are an especially effective tool, a conclusion backed up by political science. The Swanson campaign has not had the time — nor spent the resources — to set up a field operation to do this kind of persuasion.

So, can you still win with name ID and TV ads?

State Rep. Erin Murphy will test the opposite approach. After scoring the DFL endorsement at the party convention, she entered the primary season lesser known and without as much cash for ads as Swanson or Walz.

But Murphy has lots of volunteers to knock on doors and make phone calls, and a robust presence on social media. Her tweets and Facebook messages are amplified by hundreds of retweets and reposts. This helped her raise cash for more conventional ads.

The Swanson approach banks on the typical DFL primary electorate: older, whiter and tilted toward greater Minnesota.

Whereas Murphy's advantage would seem to be with ascendant generation of DFL activists and voters — younger, more diverse and more urban than the previous generations.

As for Walz, he seems to be blending these two approaches.

Soon we'll have some answers.

One and out?

Tim Pawlenty dropped a bit of a truth bomb on Forum Communications' Don Davis and me after the Farmfest forum when he said it was "highly likely" he would only serve a single four-year term if elected. When pressed, he backed off a bit, saying no announcement or decision any time soon.

J. Patrick Coolican 651-925-5042 Twitter: @jpcoolican patrick.coolican@startribune.com