WASHINGTON — As the clock ticked down Thursday on a self-imposed deadline for a breakthrough in coronavirus relief talks with no deal in sight, Jim Cramer, the brash CNBC host, had an on-air proposal for Speaker Nancy Pelosi of California.Why not try invoking the memory of the late civil rights icon John Lewis to try to persuade Republicans to agree to help the most vulnerable Americans, including “minorities” struggling to weather a pandemic and a recession?Ms. Pelosi flashed a forced smile. “Perhaps,” she deadpanned, “you mistook them for somebody who gives a damn for what you just described.”The comment — unusually coarse for Ms. Pelosi, 80, who was educated by nuns — was part insult, part dare and part slogan for a woman who believes she has the upper hand in crisis negotiations and does not intend to lose it. And it reflected how, two weeks into stalled talks over another round of federal assistance to prop up a battered economy, and less than three months before Election Day, the speaker of the House is going for the jugular.She has publicly heaped disdain on her White House negotiating partners as she plays hardball in daily private meetings in her Capitol office suite, convinced that she has political leverage to force Republicans to agree to far more generous aid than they have offered. She has been unwilling to bow to the Trump administration’s demands for a much narrower bill or a stopgap solution.“We’re not doing short-term action, because if we do short-term action, they’re not going to do anything else,” she said of Republicans Friday afternoon during an interview in her office, after negotiators blew past their own deadline without a deal. “That’s it — like a sucker punch, you know — ‘Let us just do this little bit,’ and then you know what? We’ll never see them again.”Instead, Ms. Pelosi is pushing for a sweeping package that includes billions of dollars for state and local governments and schools, food and rental assistance, and additional aid for election security and the Postal Service.All the while, Ms. Pelosi has made it clear that she does not much trust President Trump’s advisers — she has taken to asking negotiators to turn over their electronic devices before entering sessions in her office — nor does she think highly of their ability to forge a compromise. “You’ve never done a deal,” she has reminded Mark Meadows, the White House chief of staff and former congressman, according to a person familiar with the talks who described them on the condition of anonymity.Ms. Pelosi’s strategy carries substantial political risk and real collateral damage, at least in the short term. In holding out for a sweeping relief package, Democrats have swatted away Republican pleas to pass weeklong extensions of the expired $600-per-week in extra federal jobless pay that millions of Americans have relied upon, drawing Republican charges of obstruction.The impasse prompted Mr. Trump to take unilateral action on Saturday to provide relief on his own with a series of executive actions — though it remains unclear if he has the legal authority to do so. And it has sown uneasiness even among some rank-and-file Democrats, particularly those who represent politically competitive districts and are eager to show voters their party is capable of bipartisan compromise on pressing issues.“We cannot let desperate Americans and small businesses be used as pawns — even in the face of a president and Senate majority leader who appear incapable of empathy,” said Representative Dean Phillips, a first-term Democrat from Minnesota.On a private conference call on Saturday, Representative Tom Malinowski of New Jersey, another first-term Democrat, warned that a lack of an agreement would prompt his voters to declare “a pox on all our Houses. Congress is broken. Washington is broken.”“And that is great for challengers,” he added, according to a person familiar with the remarks, who spoke on the condition of anonymity.Republicans have been far sharper in their criticism of her tactics, blaming Ms. Pelosi for the lapse in jobless aid even though she included a full extension of the payments in her May legislation, which Republicans are trying to make deep cuts to.“Speaker Pelosi has refused, again and again and again, to do what’s right for the country, to work together in a bipartisan way to come up with a package to help provide relief in terms of Covid and the economic crisis,” Representative Liz Cheney, the No. 3 Republican, told Fox News Radio last week.But Ms. Pelosi, in her second round as speaker and arguably as powerful as she has ever been, has seen little reason to change course. Instead, with public opinion she says is in favor of expansive government intervention and polls showing Republicans up and down the ballot sagging under the weight of Mr. Trump’s coronavirus response, the speaker and Democrats have been emboldened to press their advantage.“At the core of her negotiations are values, and that steers her right,” said Senator Chuck Schumer, Democrat of New York and the minority leader. “It’s real. What she says out there, she says inside.”Ms. Pelosi’s hand has been strengthened by the divisions among Republicans, many of whom do not want to provide any additional aid, meaning that the White House will need broad support from Democrats to push through any stimulus plan.Ms. Pelosi set the stage for the dynamic in May, when — quick on the heels of the enactment of nearly $3 trillion in pandemic aid bills — she corralled the Democratic votes needed to approve an additional $3.4 trillion in relief. Senate Republicans waited until late last month to unveil their own $1 trillion plan, and Mr. Trump has repeatedly undercut their position.White House officials say it is Ms. Pelosi who has hamstrung the talks.“It’s interesting just to hear the comments from Senator Schumer and Speaker Pelosi saying that they want a deal,” Mr. Meadows declared on Friday, after negotiations broke up with no resolution and Ms. Pelosi addressed the news media. “Their actions do not indicate the same thing.”Senator Marco Rubio, Republican of Florida, said Ms. Pelosi and Democrats were motivated not by substantive policy differences, but by politics. They “still think it’s politically beneficial for nothing to happen,” he said.It is not the first time that Ms. Pelosi has found herself with considerable leverage in a high-stakes negotiation with Republicans at a time of crisis. During the financial meltdown of 2008, as Republicans balked at a $700 billion bailout package that George W. Bush’s administration had requested to stave off further financial ruin, Henry M. Paulson Jr., then the Treasury secretary, famously went down on one knee at the White House to beg Ms. Pelosi not to pull her support from the plan.“It’s not me blowing this up. It’s the Republicans,” Ms. Pelosi told him then, adding bitingly, “I didn’t know you were Catholic.”This time, though, it has become progressively less clear whether Mr. Trump — who has been more an irritant than an active participant in the negotiations — even wants the deal that he needs Ms. Pelosi to deliver.“Up and until now, she has rationally assumed there was some self-interest on the part of Trump that would lead to a deal,” said former Representative Barney Frank, Democrat of Massachusetts, who joined Ms. Pelosi that day at the White House in 2008. “If, in fact, that turns out not to be the case, you have a whole new ballgame to think about.”Though she acknowledges political differences with Mr. Bush, Ms. Pelosi is far more blunt about her disdain for Mr. Trump, with whom she has developed a toxic relationship.“This president is the biggest failure in our history,” she said on Friday. “I can’t think of anybody worse.”He appears to return the sentiment, referring again to Ms. Pelosi this week as “Crazy Nancy.”While she said she has had productive negotiations with Steven Mnuchin, the Treasury secretary — so much so that Mr. Mnuchin has felt compelled to privately answer complaints from Republicans that he has given too much — she is more skeptical of Mr. Meadows, who made his name in Congress blowing up bipartisan deals from the right, not constructing them. Talks have been “less efficient” than the discussions that led to the first phases of pandemic relief, she said.“Mark Meadows is in the room as an enforcer,” she said, adding that she was not sure whether “he’s a clone for the president, or the president’s a clone for him.”Ms. Pelosi said she also questioned the overall approach of the administration, comparing their negotiating tactics to “Sophie’s Choice,” a film in which a mother must choose which of her children to send to their death.At one point during one of the negotiations, Mr. Mnuchin had inquired what WIC, a nutritional program specifically for women, infants and children, was, according to a person familiar with the talks.“On any given day, you might say, why am I even talking to these people? They don’t care,” Ms. Pelosi said. “But the fact is, we’re there — we have an opportunity to do something.”Luke Broadwater contributed reporting.