Scott Pruitt has shown an astonishing ability to stay on as director of the Environmental Protection Agency through scandals that would have felled nearly anyone else. President Donald Trump fired Tom Price, the secretary of Health and Human Services, over less.

Price was under fire for inappropriate taxpayer-funded travel. Pruitt has been accused of the same — and also of having his security detail run sirens so he could get to dinner at a nice French restaurant on time. And of trying to use his office to arrange a fast-food franchise deal for his wife. And of renting a condo from a lobbyist at a below-market rate. And of making an aide find a discount mattress for him. And probably more by the time you read this. He is already the subject of 12 federal investigations.

But Pruitt’s luck may be running out, for four reasons.

First, the ethics hits keep coming. The steady accumulation of bad stories about Pruitt has worn down some of his defenders. A single story could be dismissed as an invention by Pruitt’s political opponents; a second as a Pruitt mistake that was getting blown out of proportion. Anyone who defends him now has to expect fresh embarrassments.

Second, the scandals are taking a toll on his perceived effectiveness. One reason Price got the boot while Pruitt hasn’t is that Trump has been more successful on environmental than on health issues. Pruitt was seen to be delivering for Trump’s coalition while Price wasn’t. But Pruitt’s top aides have been deserting him, and dealing with investigations and bad publicity is taking up a lot of his time. At this point any initiative that comes out of Pruitt’s EPA will immediately be suspect as having a corrupt motive.

Third, conservative support for Pruitt is waning. Republican lawmakers, including very conservative ones, are starting to express their unhappiness with Pruitt on the record. Matt Lewis wrote a scathing article about him that noted that other conservative commentators are abandoning him. I spoke to one conservative leader who signed a letter in early April supporting Pruitt in an earlier phase of his scandals; he says he would not do it today. Two other signers expressed frustration with Pruitt’s continued misbehavior. (He still has the strong support of others.)

Fourth, there’s a potential replacement in place. Andrew Wheeler, a former aide to conservative Republican Senator James Inhofe, was confirmed as deputy director of the EPA in April. If Pruitt resigned or were fired, Wheeler would become acting director. The Trump administration therefore doesn’t need to go through a bruising confirmation battle to ensure that a conservative runs the agency after Pruitt.

Pruitt has given no sign that he has a sense of shame that might drive him from office. But his situation is deteriorating, enough so that Trump could find that he is more trouble than he is worth.

PONNURU, Ramesh Bloomberg News