Jon Tester was on his farm in rural Montana when his phone rang with the news: It was his chief of staff, informing him that the president of the United States had just called for his resignation on Twitter.

The Montana Democrat briefly considered President Donald Trump’s latest attack on him, then fired up his tractor and went on his way. Tester wasn’t going to get into it with Trump over the senator’s role in bringing down the president’s Veterans Affairs nominee, Ronny Jackson.


“It’s spring planting on the farm. Would I have liked to have been out pushing back on some of this? Sure. But I couldn’t, I was farming,” Tester said in an interview. “Truthfully.”

After laying into Tester in late April, Trump is reveling in a new round of attacks on the 10 senators up for reelection in states that the president won in 2016. Always more of an attack dog toward his enemies than a defender of his allies, Trump is laying into “Sleepin’” Sen. Joe Donnelly of Indiana, calling Sen. Bob Casey of Pennsylvania a “disaster” and blaming Sen. Sherrod Brown of Ohio for “catch and release” immigration policies.

And Democrats are responding with a shrug, total silence or, in West Virginia Sen. Joe Manchin’s case, effusive praise for the commander in chief. Vulnerable Senate Democrats have made a conscious decision not to engage Trump on his terms, after watching the president tear apart the GOP primary field in 2016 with personal insults, derisive nicknames and political broadsides.

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Trump has 52 million Twitter followers and the bully pulpit of the presidency. And Democrats know that when he gets locked in a beef with someone, the person on the other end of the conflict often comes out worse for it.

“They’re not interested in getting into a big food fight with President Trump,” said Maryland Sen. Chris Van Hollen, chairman of the party’s campaign arm. “That’s President Trump’s style, not their style.”

Trump’s zeal for political swipes at Democrats who’ve opposed his agenda is a critical X-factor heading into campaign season, as is Democrats’ strategy of silence in responding to him. Van Hollen said voters “are not going to just blindly listen” to Trump, though Trump’s Republican allies are warning that the president could easily tip the balance in close races.

And with a map stacked with Democrats up for reelection in states that Trump won, the president is itching to take on a Senate Democratic Caucus that he views as uncooperative and antagonistic.

“You’ll probably see the president traveling more after Memorial Day. You’ll see him going to places like Montana,” said Marc Short, the president’s top legislative aide. “It’s probably not in their best interest to be in a fight with the president.”

All the evidence suggests that Democrats agree.

Confronted with President Donald Trump’s derisive nickname for him, Donnelly merely chuckled and reiterated his focus on Indiana. Sen. Bill Nelson of Florida said his reaction to Trump’s attacks on his immigration votes is simple: “I don’t do anything.”

While bashing Sen. Debbie Stabenow, Trump even dinged her state’s voters for electing a Democrat who had voted against his tax cut bill and against more draconian border security. “It’s your fault” for reelecting Stabenow, Trump said during a Michigan rally last month.

Stabenow refused to counterpunch: “People in Michigan know me,” she said in a brief interview. “It’s OK.”

Before and since Trump took office, Brown has gone out of his way to highlight his shared views with the president on trade. This week, the Ohio Democrat repeated his openness to finding common ground.

But of the 10 most vulnerable Democratic senators up for reelection, Brown came the closest to expressing exasperation with the president’s frequent insults of his colleagues. Trump flew to Ohio this month to blast Brown, concluding he “does not think the way we think” on immigration and health care policies.

“I shake my head at a president of the United States that calls people names,” Brown said. “I don’t know any adults that do things like that.”

Trump has increasingly focused his ire on Senate Democrats up for reelection the past few weeks, blaming them for stalling his nominees and voting against tax reform. The president has always appeared at his best in front of conservative crowds, and Republicans say he’s raring to go on the offensive after spending 17 months defending himself and his administration.

Plus, Senate Majority Leader Mitch McConnell (R-Ky.) and his allies have impressed on Trump how important holding the Senate is.

“The president is all in,” said Senate Majority Whip John Cornyn (R-Texas). “He understands with great clarity the importance of successful midterms.”

In a private meeting with Senate Republicans this week, Trump mocked Donnelly and Manchin. He joked that Manchin tries to hug him all the time and that the West Virginia senator has a big problem in November because of Trump’s popularity in his state. Last month, Trump zinged Manchin as someone who “votes against everything” that the president prefers.

Manchin’s response was nothing but kindness.

“Once the election is over and that person is president, that’s my president. And I want them to be successful,” Manchin said.

Trump started off with warm relationships with Manchin and Sen. Heidi Heitkamp of North Dakota, inviting each of them to Trump Tower to interview for Cabinet posts. But he’s since soured on them after they opposed tax reform.

Though Heitkamp pushes back at the administration more often than Manchin, she’s also intent on killing Trump’s campaign against her with kindness. Heitkamp rattles off areas where she aligns with the White House: Partnering with Ivanka Trump to fight sex trafficking, rolling back water rules and deregulating the banking industry.

“I think we share a lot of the same goals,” said Heitkamp, who wasn’t included in Trump‘s latest fusillade on Democratic senators. “That doesn’t mean that I won’t eventually get called out.”

Even Sen. Claire McCaskill of Missouri, a famous political brawler, said she’d pass on a potential tit-for-tat with Trump.

“I’m going to disagree with him on the policy, not the personality,” she said.

To Democrats, Trump’s campaign against GOP Sens. Marco Rubio of Florida and Ted Cruz of Texas is instructive. Trump belittled Rubio as “Little Marco” and Cruz as “Lyin’ Ted,” threatening to “spill the beans” on Cruz’s wife and tying his father to the JFK assassination.

“It’s dangerous for them,” said Sen. John Thune of South Dakota, the No. 3 GOP leader. “If they get in a fight with them, like on Twitter? … It’s going to be really harmful.”

It can take some work to draw Trump’s fire; Tester’s release of damaging information about Jackson made headlines, but that was an unusually conspicuous poke of the bear. There are so many Democrats up for reelection in competitive races that not all of them are yet on Trump’s radar.

Somehow Sen. Tammy Baldwin (D-Wis.), who has a tough race in the fall, has thus far escaped Trump’s wrath — despite being one of the most liberal members of the Senate and voting against many of his high-profile nominees.

Baldwin declined to comment when asked how she would handle a future punch from Trump, lest she draw attention to the omission.