Mike Bloomberg is lagging behind his Democratic competitors in the polls, and he will not appear on the next presidential debate stage or on the ballot in Iowa, New Hampshire or South Carolina.

But the former New York mayor has attracted the obsessive attention of President Trump, who is annoyed by Bloomberg’s constant ads targeting him, concerned about the billionaire’s outsize spending, focused on his growing numbers in the polls and seemingly fixated on his TV appearances.

The president has repeatedly attacked Bloomberg on Twitter, calling him “Mini Mike” to insult his small stature, and frequently focused on him in conversations with campaign advisers and White House officials.

“It’s very clear that the ads we are running have gotten under his skin because they are effective,” said Howard Wolfson, a senior Bloomberg aide. “Mike’s poll numbers are improving, the president is screaming. Mike is a data-driven guy. When he sees data is working, he doubles down.”

Wolfson said to expect more blistering ads against the president in coming months. So far, Bloomberg’s spots have targeted Trump over impeachment, his position on vaping, his health-care-policy decisions and his relationship with the military. Many have prompted rapid responses from Trump, sometimes minutes after they air.

Bloomberg campaign manager Kevin Sheekey debuted a new ad on “Fox & Friends” on Thursday that cited a new book by two Washington Post reporters, who chronicle how Trump lashed out at U.S. military leaders, characterizing them as “dopes and babies.” Trump responded shortly after the spot aired.

“Mini Mike Bloomberg is playing poker with his foolhardy and unsuspecting Democrat rivals,” Trump tweeted. “The fact is, when Mini losses [sic], he will be spending very little of his money on these ‘clowns’ because he will consider himself to be the biggest clown of them all — and he will be right!”

Trump’s advisers have repeatedly encouraged the president to focus on other opponents instead. Campaign manager Brad Parscale and senior adviser Jared Kushner have warned against giving Bloomberg more attention and do not see him as the threat that Trump does, aides have said. There is no plan for the campaign to target him with advertisements at this point, advisers said.

Trump has repeatedly brought up Bloomberg — calling him “evil,” in the words of one close adviser — and said that he wants to destroy Trump with unrelenting money, even if the president does not believe Bloomberg can win, according to aides.

He has called Bloomberg’s ads “lies” that are unfair depictions of his record in the White House. Several advisers have said the president also references Bloomberg’s 2016 Democratic convention speech as a sore point and repeatedly asks advisers about his polling numbers, which have hovered below 10 percent in public surveys.

Other advisers have sought to elevate Sen. Bernie Sanders (I-Vt.), hoping that a leftist candidate could give Trump a good foil in the general election.

Parscale said this week that he would only worry about Bloomberg if he surpassed former South Bend, Ind., mayor Pete Buttigieg and Sen. Elizabeth Warren (D-Mass.) in the Democratic race.

“It’s a free country, and he can set his money on fire if he wants to. He’s still in a statistical tie with the back of the pack in the Democrat field,” said Tim Murtaugh, a Trump campaign spokesman.

Trolling the president is different from convincing skeptical primary voters and defending his own record on issues such as stop-and-frisk policing in New York City. Bloomberg endorsed George W. Bush, for instance, and welcomed the Republican National Convention in New York in 2004.

But his path to the nomination could become clearer if former vice president Joe Biden stumbles in Iowa and New Hampshire, creating an opening for Bloomberg to use his significant advertising budget to argue that he is the most electable alternative.

In the meantime, the campaign has been using attacks on Trump as a rallying cry, both to recruit staff to his campaign and to convince Democratic primary voters that his campaign is more than the vanity project of another billionaire candidate.

Sheekey said the campaign will either be the “best primary campaign in American history” or the greatest independent spending campaign against an incumbent president that has ever been created.

As it stands, the Bloomberg advertising campaign is squarely focused on states that could help get Bloomberg the nomination, with only about 1 in 4 dollars going to the six swing states that his advisers expect to be competitive in the general election, according to Facebook ad spending data and a source familiar with the television buys, who spoke on the condition of anonymity because that person was not authorized to share the information publicly.

But that swing-state spending has still been considerable. Through Jan. 11, Bloomberg has spent $198 million on television advertising, including more than $47 million for spots in the projected swing states of Arizona, Florida, Michigan, North Carolina, Pennsylvania and Wisconsin. On Facebook, he has blasted another $3.6 million to voters in those states.

Before the year is over, he has promised to spend $100 million on a digital effort to defeat Trump in swing states, and he has committed millions more to an effort to register 500,000 new voters in those states. He is also building a data operation that he intends to use to elect a Democratic president whether or not he is the nominee, his advisers say.

In an interview, Wolfson said he wanted to draw a contrast with Democrats, who are attacking one another in New Hampshire and Iowa. Bloomberg has not competed in those states, knowing he would be unlikely to fare well, and is focused on Super Tuesday on March 3.

“We’ve chosen a different path. They are in Iowa and New Hampshire attacking one another. We’re making the case against Donald Trump,” Wolfson said. “Voters among all else are looking for a candidate that is best qualified to take on Donald Trump in a general election.”

Many of the ads Bloomberg has run include some mention of Trump, with many of the spots focusing on the president’s perceived weaknesses among swing voters.

“Health care is a huge vulnerability for him,” Wolfson said of Trump. “It’s the issue that won the Democrats won the midterms. It is difficult for him to defend his own record on health care.”

Bloomberg’s aides also plan on using the ground campaign that Bloomberg is building against Trump, whether or not he wins the nomination. Those hired in potential general-election swing states — 60 in Arizona and more than 80 in North Carolina, for example — have been told they will have a job through the summer conventions or the November elections to organize against Trump.

Bloomberg seems to have approached the endeavor as a no-risk proposition, given that he has decided that defeating someone he calls an “existential threat to our country” is one of his top priorities.

“My Plan B is a hell of a lot better than anybody else’s Plan A,” he has told advisers, according to one aide, who spoke on the condition of anonymity to describe private conversations.

Either Bloomberg wins the nomination and the presidency or he remains the 12th-richest person in the world with a chance of taking credit for defeating Trump.

 On the stump, Bloomberg seems to delight in needling Trump, calling him a “real estate promoter” and not a businessman. He will recount the phone call from Trump after the 2016 election, when the president-elect offered his cellphone number. Bloomberg says he didn’t bother to write it down.

 Bloomberg also repeats an anecdote about Trump not knowing how to use a New York City subway card when they rode together many years ago. Trump has said this description is untrue, saying the gates were opened for them because they were traveling with a large entourage.

“I never had a MetroCard when I rode the subway with him,” Trump told The Washington Post last year.