Sarah Huckabee Sanders, the White House press secretary, however, noted that Mr. Kushner was still seen internally as one of the administration’s most successful negotiators, pointing to his involvement with the criminal justice bill as well as the new North American trade deal. “Jared is a key player in the administration and will continue helping the president accomplish his top priorities,” she said in an email.But for now, Mr. Kushner appears to have few allies, occupying what people close to him describe as a no-win position.Mr. Kushner finds himself with little sway over Democrats, who consider the substantial changes that the White House keeps proposing for asylum seekers to be poison pills. And conservatives are not convinced Mr. Kushner is the right person to negotiate a deal. They recognize he has Mr. Trump’s ear, but worry he does not understand the fault lines of the debate or what proposals will anger Mr. Trump’s base. One proposal that was reviewed, which would give green cards to 700,000 undocumented young immigrants, enraged conservatives.Within the White House, several aides said, Mr. Kushner is not interested in opinions that vary from his, and tends to view people who disagree with him as problems, closing them out of discussions. People close to Mr. Kushner, however, speaking on the condition of anonymity, have described him as working well with West Wing colleagues, particularly the legislative affairs director, Shahira Knight, a veteran of Capitol Hill.But even Mr. Kushner’s allies concede that when it comes to immigration, he has not grasped the emotional nature of the fight the way he did when he tackled the criminal justice overhaul, an issue that was personal because of his father’s own incarceration.Mr. Kushner, allies said, sees the $5.7 billion request for border wall money as reasonable, and has compared it to one month of troop deployments in Afghanistan. He views Ms. Pelosi as “trophy hunting,” or trying to take down the president politically with the shutdown.