A conservative group with Tea Party ties is launching radio and television ads supporting former George W. Bush appointee Mike Sullivan in his bid for the Republican nomination for Senate in Massachusetts's upcoming special election.

But the Conservative Campaign Committee's effort could backfire in the state, where Tea Party affiliation could turn centrists off from a Republican candidate.

The group has already raised $50,000 for the effort, according to spokesman Ryan Gill, and hopes to raise $200,000 to spend in the primary campaign.

It will launch two 60-second radio ads and a 60-second and 30-second television ad touting Sullivan's conservative credentials next week, Gill said.

The radio ads contrast Sullivan with his two Republican opponents: state Rep. Dan Winslow and local businessman Gabriel Gomez. The ad targeting Winslow notes his many contributions to Democrats in state legislative races, totaling at least $2,300 since 2003.  

Sullivan and Gomez have also contributed to Democratic candidates, but fewer than Winslow.

"There is a better choice: Common-sense conservative Michael Sullivan," the narrator says.

"Endorsed by the Conservative Campaign Committee and Massachusetts Citizens for Life, Michael Sullivan is the Republican we can trust for U.S. Senate," the narrator closes.

The ad targeting Gomez charges that he "has acted like anything but a Republican," noting that he supported President Obama in his first run for president. It also highlights a controversial letter released by his campaign revealing he had pledged to support Obama if appointed to the open Senate seat he is now pursuing in the special election.

"…in a vain attempt to get appointed to the U.S. Senate, Gomez promised Democrat Governor Deval Patrick it would be good for Democrats to have him in Washington and he'd advance the Obama agenda on immigration and gun control," the narrator says.

It goes on to repeat the same line from the Winslow ad, that Sullivan is the "common-sense conservative" in the race.

The television ads are entirely positive spots, featuring real Sullivan supporters sharing why they're voting for him on camera.

But Sullivan's campaign distanced its candidate from the effort.

"We are not familiar with the group, the individual running it, nor the message they may try to send," said Sullivan spokesman Alicia Preston in a statement to The Hill.

That runs counter to a comment given by Sullivan campaign manager Paul Moore to the Boston Globe last week. Moore said, in response to a Globe piece on the group, that "anyone who wants to get out and help Mike is welcome to get out and help Mike."

The newly lukewarm reaction to CCC's support reflects the difficulty Sullivan could face in a general election in Massachusetts if he's tied to the group. The CCC, formerly known as the Campaign to Defeat Barack ObamaBarack Hussein ObamaAll five living former presidents to attend hurricane relief concert Overnight Health Care: Schumer calls for tying ObamaCare fix to children's health insurance | Puerto Rico's water woes worsen | Dems plead for nursing home residents' right to sue Interior moves to delay Obama’s methane leak rule MORE, is headed by Tea Party activist Lloyd Marcus.

Marcus has expressed staunch opposition to the gay-rights movement, calling it "dangerous," "relentless, vicious and hell-bent" on achieving equal rights for gays, and accusing gay-rights advocates of attempting to "indoctrinate" young Americans in a post on conservative site BizPac Review.

In another post, Marcus accused Obama of "leading a socialistic secular progressive anti-America movement" and said that, for black supporters of the president, "Obama's black skin [is] trumping everything."

Gill said that Marcus's comments were a "distraction" from the real issues in the race, and had nothing to do with Sullivan's conservative credentials.

"For the most part, that is something that gets concocted as an attempt to create controversy when there is not an issue. [Marcus' comments are] unrelated and not our focus in this campaign," he said.

Sullivan, however, is considered a frontrunner in the GOP primary, and to make it through the general in Massachusetts, which leans Democratic, he'll have to run a centrist campaign. Any ties to a controversial Tea Party figure could work against him if he wins the nomination.

And ads framing him as a "common-sense conservative" could be used by his eventual Democratic opponent, just as Sen. Elizabeth WarrenElizabeth Ann WarrenOvernight Finance: Lawmakers grill Equifax chief over hack | Wells Fargo CEO defends bank's progress | Trump jokes Puerto Rico threw budget 'out of whack' | Mortgage tax fight tests industry clout Michelle Obama is exactly who the Democrats need to win big in 2020 Wells Fargo chief defends bank's progress in tense Senate hearing MORE (D-Mass.) defeated former Sen. Scott Brown (R) in part by tying him successfully to the national GOP.

But Preston, Sullivan's spokeswoman, said the campaign believes Marcus's comments will ultimately have no effect on the campaign, noting that Sullivan "has never even heard of" him.

"Those who know Mike, know, throughout his career and life, he has always worked to unite people, always found good in others, and has never stood by when others made hurtful or hateful remarks. We are confident the voters will judge Mike based on who is, what he has done, and how he intends to best serve the people of Massachusetts and not the personal opinions of someone he has never even heard of," she said.

Winslow, Sullivan and Gomez will face off in the April 30 primary, while Reps. Edward MarkeyEdward (Ed) John MarkeyDems lambaste Trump’s ‘outrageous’ EPA chemical safety pick Dems plan to make gun control an issue in Nevada Dem senator pitches ideas for gun control after shooting MORE (D-Mass.) and Stephen Lynch (D-Mass.) are vying for the Democratic nomination.

--This piece was updated at 9:20 p.m. to reflect a previous Boston Globe report.