(Jabin Botsford/The Washington Post)

President Trump plans to intensify his outreach to Senate Democrats this week as he tries to broaden support for massive tax cuts, but the administration’s prior overtures have left key lawmakers wondering whether the president is willing to negotiate with Democrats or solely seeking to use them as political props.

Trump on Wednesday will meet with Democrats and Republicans on the Senate Finance Committee, the panel that writes tax law, as part of an effort to curry congressional favor for his proposal, which is still in outline form, to cut tax rates for corporations and individuals.

The meeting comes after Trump and other White House officials spent months setting up events with key Democrats to both cajole and threaten them into backing the tax cuts. Some White House officials believe Democrats — even centrists up for reelection in conservative states next year — can’t be counted on. But others believe the support from even one or two could make the difference between failure and success.

Trump on Monday said it was possible that “three or four” Democrats might end up supporting the tax cut plan, but he also said it’s possible  every Senate Democrat votes in opposition.

“We may get no Democrat support and that’s because they are obstructionist and they basically want us to do badly, and that’s not going to happen,” Trump said after meeting with Senate Majority Leader Mitch McConnell (R – Ky.).

He added that changes were being made to the tax proposal that appeared to be in line with demands made by some Democrats.

“We want to make sure that the middle class is the biggest beneficiary of the tax cuts and the tax reform,” Trump said. Many Democrats have said the vast majority of benefits from the GOP tax plan would go towards the wealthiest Americans and not the middle class.

Republicans control 52 votes in the 100-seat Senate, and some GOP members have raised the possibility that they might not sign off on massive tax cuts that increase the debt. Republicans want to pass the tax plan through a process known as “reconciliation” that requires a simple majority of support but that could still require them to secure help from a handful of Democrats.

The outreach comes at a pivotal time. The White House and Democrats are lurching toward an increasingly acrimonious showdown over immigration, health care and government spending. Fights over each of these issues is expected to trigger a showdown in early December that — if left unresolved — could lead to a government shutdown. Senior White House officials are trying to isolate the tax issue with several Democrats and hope the other political brawling doesn’t spill into the tax discussions.

That’s why the White House has made cautious but calculated outreach to Sens. Joe Manchin III (D-W.Va.), Heidi Heitkamp (D-N.D.), Jon Tester (D-Mont.) and Joe Donnelly (D-Ind.), with Heitkamp and Donnelly flying on Air Force One and appearing with Trump at tax cut rallies. Each of these Democrats comes from states that overwhelmingly supported Trump in 2016.

“If Senator Donnelly doesn’t approve it, because you know he’s on the other side, we will come here,” Trump said in a September speech in Indiana, while Donnelly stood in the audience and listened. “We will campaign against him like you wouldn’t believe. I think they’re going to approve it. … I think we’ll have numerous Democrats come across because it’s the right thing to do.”

Senate Democratic aides said it remains unclear how much the White House wants to negotiate, complaining that they so far remain cut out of discussions as House and Senate GOP leaders draft legislation. Democrats have said they want to ensure the bills help small businesses and the middle class, as well as avoid adding much, if anything, to the debt. They have also raised concerns that the GOP plan as presented so far could overwhelmingly benefit the wealthy.

Heitkamp, North Dakota’s former tax commissioner, joined Trump on stage during a tax speech last month. She has heard little substantive follow-up from the White House since then, according to people briefed on the relationship who spoke on the condition of anonymity to discuss the working relationship. She wants the upcoming plan to secure tax benefits for retirement and to make it easier for families and companies to file tax returns, among other agenda items.

The White House and GOP leaders have issued a nine-page tax framework but left out many other details. Democrats — and even some Republicans — have said they are still searching for how the tax package might work if it is passed into law.

Heitkamp has been so eager to reengage that earlier this month, she approached a senior administration official at a separate White House event this month and said she hopes to continue working with them on this. But her office has heard little since.

Other Democrats have had similar experiences.

Last month when reports surfaced that Trump might want to visit Montana to put pressure on Tester to support a tax deal, he reached out with a letter to the White House, saying he wanted to collaborate “in an open and transparent manner” and that he’d be happy to meet with Trump if he opted to visit his home state.

But Tester, like other Democrats, told Trump in his letter that any reform plan “needs to be crafted in the light of day through a bipartisan process” and would have to include input from rural states.

In the weeks since the letter, Tester’s aides have heard from lower-level White House staffers, but the senator has not been approached by the president, Vice President Pence, White House Legislative Affairs Director Marc Short, Majority Leader Mitch McConnell or any other senior Republicans, according to aides.

“White House staff has said they’re interested, but it’s been broad strokes, no dates, no specifics, just the acknowledgment that they got our letter and they’re interested in going to Montana sometime but without any firm commitments,” said one aide, granted anonymity to speak frankly about ongoing talks.

The Democrat who has had perhaps the most engagement is Manchin, who spoke with Pence in August on the sidelines of an event at the Greenbrier resort in West Virginia. The next day, Manchin recounted “a good conversation,” as he made clear, “I want to be involved and help in any way I can.”

But Manchin has also stressed that the tax cuts can’t add much to the federal debt. Trump has proposed lowering the corporate tax rate from 35 percent to 20 percent, but Manchin thinks it should be closer to 25 percent. He also thinks businesses that are structured in such a way they pay their taxes through the individual income tax code should pay at a 30 percent rate, higher than the 25 percent sought by Trump.

“We both agree that they understand that they need help from Democrats and I wanted to make sure they knew that this is one Democrat that wanted to be involved and help,” Manchin said in an August interview. Since then, Manchin has attended a White House dinner with Trump and other moderate Democrats and met face-to-face twice with Short.

Wednesday’s meeting is expected to include Sen. Claire McCaskill (D-Mo.), a member of the Finance Committee who has  been critical of Trump’s approach so far. McCaskill has spent weeks pushing the White House to work more closely with Democrats on the tax plan, saying that a failure to work with Democrat doomed their efforts to make changes to health care rules.

But even though McCaskill is up for reelection in 2018 and comes from a state Trump won handily, she is digging in against the White House’s tax plan more than many of her colleagues, convinced voters will see it as a big handout for the rich.

During a meeting last week with constituents in Washington, Mo., McCaskill asked everyone to put a question on a slip of paper and drop it into a fishbowl.

The third question McCaskill plucked from the bowl asked simply, “Will you help get tax reform done this year?”

“I hope so. I would love to get tax reform done,” she said. “But here’s the issue. The issue is what is the tax reform bill? Now, I haven’t seen a final plan. We’ve seen an outline and the outline is very troubling to me.”

She explained that she’s “not interested in reducing taxes for the [wealthiest] 1 percent. I am very interested in reducing taxes to the middle class and to families that are living paycheck to paycheck. … That’s where my focus is.”

McCaskill then turned to notes on a lectern, telling the audience that she had asked staffers to determine how much money a Missouri family of four earning $50,000 would end up paying under the Republican proposal.

“Under the current law, their tax bill with the personal exemptions and the standard deduction and the child tax credit and the earned income tax credit, currently they’d pay $107 in taxes,” she said. But because the Republican plan would eliminate personal deductions, that same family would pay $887 in taxes if Trump gets his way.

Many in the room gasped.

“The family of four making $50,000 is going to pay more for taxes — that’s not middle-class tax relief,” she said, while noting that Republicans had not yet determined what they will do about the child tax credit.

White House officials have said number crunching of this sort is wildly inaccurate, and they have said Democrats and budget experts need to wait until there are more details before they know what the impact on any family or worker will be. And Senate Republican aides have said Democrats will have numerous opportunities to offer ideas that could be incorporated into the tax package when Senate Finance Committee Chairman Orrin G. Hatch (R-Utah) solicits ideas in the coming weeks for the bill he will try to push through the chamber.

Trump has promised that the tax cut plan will deliver major savings for the middle class, but they are still working out details of how this can be achieved.

These are the specifics that will likely determine whether Democrats up for reelection in 2018 consider backing the bill, or whether they decide to lock arms with their more liberal colleagues and oppose it.

Democrats are expected to take different approaches, with some like McCaskill already digging in against the White House’s strategy and others, like Manchin, willing to give the White House more time. Eventually, though, each of these lawmakers will have to make a decision

Retired senator Kent Conrad (D-N.D.) said Democrats would be best served by separating their decisions on taxes from other legislative fights, to see if they could come up with a solution that best helps their constituents.

“You start out listening and interacting and if that proves not to be fruitful, you are left with no recourse but to be in opposition,” he said.