Maybe this race isn’t as close as advertised.

Despite two new public polls showing a 7-point race, the Republican-aligned outside groups that swamped the 2012 landscape with TV advertising are still nowhere to be found in the special election for Senate in Massachusetts.

American Crossroads, the U.S. Chamber of Commerce and other groups generally supportive of Republican candidates have so far declined to jump into the race. They have not spent a dollar in the Bay State, although the contest has become more competitive than expected in recent weeks.

Even a super PAC created specifically to support GOP nominee Gabriel Gomez, the Committee for a Better Massachusetts, has launched only a handful of radio ads on his behalf since the primary, according to Federal Election Commission filings.

There’s still time for these groups to play in the race ahead of Gomez’s June 25 showdown with Democratic Rep. Edward J. Markey. But the window is closing: Unless Tuesday night’s debate is a game-changer, the big-spending groups are on track to sit this race out.

So far, Democratic groups and candidates have spent three times as much as Republicans in the special election, according to a GOP source tracking ad buys. As of last week, national Democrats — including a prominent super PAC — had spent $1.25 million on ads to help Markey.

Ryan Williams, a New England-based Republican strategist and former aide to Mitt Romney, said Gomez’s current standing in the polls is already beyond expectations. He pointed out that President Barack Obama won the state last year by 23 points.

None of the outside groups would comment on their plans for the race, but Williams said they are no doubt still watching closely.

“For any Republican to win in Massachusetts, they have to catch lightning in a bottle in the final month,” Williams said. “And I think he has the opportunity to do that.”

Meanwhile, a band of organizations aligned with Democrats have already stormed the Massachusetts airwaves, streets, Web and mailboxes for the final sprint to boost Markey and paint their own picture of Gomez.

Obama is scheduled to headline a rally in Boston on Wednesday to raise Markey’s profile. He’ll also increase awareness about the oddly timed election, which comes as schools are letting out for the summer and families begin vacations.

The onslaught of spending and big-name Democrats on the stump is aimed at halting any potential for the second coming of Scott P. Brown. The stain of the former GOP senator’s shocking 2010 victory serves as the party’s painful reminder of the uncertainty that nearly any special election can bring — even in the blue Bay State.

Democrats are pulling out all the stops, but party operatives maintain it’s merely insurance — not an emergency measure.

“We got a bit of a warning shot when Scott Brown got elected. So I don’t think anybody wants to take any chances,” Massachusetts Democratic consultant Jim Spencer said. “In a special election, anything can happen.”

Still, Democrats are laying down some serious cash. The Democratic Senatorial Campaign Committee and Senate Majority PAC purchased a combined $1.25 million in TV ads that hit the air last week, tying Gomez to national Republicans.

The League of Conservation Voters, which spent nearly $850,000 on a field program for Markey in the primary, announced last week that it spent some $400,000 on direct mail to reach 150,000 households in the state. NextGen Committee, a super PAC founded by billionaire Tom Steyer, is also spending six figures on a field and social-media campaign.

“Democrats are very worried or they wouldn’t be spending that money. It’s that simple,” said Republican media consultant Erik Potholm, a Maine native. “Wouldn’t Democrats rather save that money for the 2014 elections? Of course they would.”

Markey and Gomez were scheduled to debate Tuesday night. At the same time, Vice President Joseph R. Biden Jr. and former Vice President Al Gore were scheduled to headline a fundraiser in Washington, D.C., for Markey. First lady Michelle Obama did the same for Markey in Boston on May 29.

Markey packed last weekend with stump partners including Democratic National Committee Chairwoman Debbie Wasserman Schultz of Florida, Democratic Caucus Chairman Xavier Becerra of California and Rep. Joseph P. Kennedy III of Massachusetts.

“Democrats are taking nothing for granted,” DSCC spokesman Matt Canter said. “We’re going to do whatever we need to do to make sure we’re successful in this race.”

Gomez has downplayed his ties to the national party. The only national Republican to stump for him was Sen. John McCain, R-Ariz., a fellow Navy veteran who twice won the Republican presidential primary in neighboring New Hampshire.

But Gomez has received help in coordinated TV ad buys.

The Markey campaign has outspent the Gomez campaign on TV about 2-to-1, according to a GOP source tracking ad buys. Markey spent about $2.7 million for TV time between May 8 and June 15, while Gomez spent a little more than $1.3 million.

About $800,000 of Gomez’s TV spending was paid for by the state Republican Party. The National Republican Senatorial Committee has not commented on whether it transferred that money, but the state party had less than half that in cash on hand as of April 30.

“From day one we’ve made clear that the NRSC believes Gomez can win and have acted accordingly,” NRSC spokesman Brad Dayspring said.