The ad buy is modest. The No Downtown Stadium group paid $5,000 to put ads on local television through the weekend. The first ad ran during Wednesday's Country Music Association Awards broadcast.
Measure C would raise the city's hotel tax so a public agency can borrow more than $1 billion to help build a stadium convention center complex.
Measure C opponents said it is good to be visible before the election, however, the idea isn't to persuade, but to remind.
"It is not the type of measure where you have to do extensive education of the public. It is really confirmation that what they already believe is right," said April Boling of the No Downtown Stadium group.
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The Chargers have a much more pronounced media footprint. The team has spent millions of dollars on the effort to get Measure C passed. That includes money for television and web advertising, and door-to-door campaigning.
"We are never going to have the amount of money to spend that Spanos has. You know, that's just the long a short of it," said Boling. "And so we've had to depend on getting the word out through word of mouth and through various forms of other media."
Meanwhile, Chargers owner Dean Spanos rallied the faithful in downtown San Diego on Friday. He asked for support to pass Measure C on election day.
Spanos joined San Diego Mayor Kevin Faulconer and several former Chargers players to urge voters to support a measure that helps the team build a new downtown stadium and convention center complex. Spanos remained focused on passing Measure C and he has not considered what happens if the measure fails at the ballot box.
"As I said, I am waiting 'til Tuesday. I want to see the results. I want to see the support we get, or we don't get," Spanos said. "And then I'm going to take some time afterwards and evaluate my options at that point. But until Tuesday comes and to actually see what the numbers are and what the support is I'm not going to make any speculated guesses right now."