The successful confirmation of President Donald Trump’s cabinet nominees continued when senators voted 53-to-47 to confirm Steven Mnuchin as Treasury Secretary Monday.

Mnuchin is a Wall Street financier, who has worked for Goldman Sachs and ran his own investment funds and vehicles. In the 2016 presidential campaign, Mnuchin was the national finance chairman for the president’s campaign.

After the “Great Recession,” in 2009, Mnuchin and his partners and investors purchased IndyMac, a troubled California bank that was in the center of the real estate boom and bust. Six years later, after Mnuchin renamed the bank OneWest and worked through its issues, he sold it off. However, Democrats targeted the way Mnuchin and his team worked through the issues, claiming that he was insensitive to people losing their homes because they could not keep up with mortgages from the old IndyMac bank.

The chairman of the Senate Finance Committee, Sen. Orrin Hatch (R.-Utah), said on the Senate floor shortly before the vote that these allegations were unfair and untrue.

Hatch said there was a double standard for nominations. For a Republican nominee any charge, no matter how flimsy, was enough for Democrats to oppose a nominee. But, for Democratic nominees, no charge ever seemed enough.

Republicans hold a 52-to-48 advantage in the Senate, which means that if three GOP senators defect, Democrats have the votes to defeat the confirmation of a Trump appointee–not inconceivable given the president’s difficult relationship with some Republican senators.

But it has been the Democrats themselves who have all but guaranteed the success of Trump’s cabinet picks, because of their strategy of resisting nearly every nomination with a spirit of animus. Unlike the House, the Senate operates on personal relationships, with most senators hesitant to engage in partisanship, unless it is forced upon them.

Both leaders of the Senate Democrats, Minority Leader Charles Schumer (D.-N.Y.) and Minority Whip Richard Durbin (D.-Ill.), have developed strong working relationships with Senate Republicans, and both men prefer working out differences privately, so that floor votes are merely a formality.

Enter the other leaders of Senate Democrats, Sen. Elizabeth Warren (D.-Mass.) and Sen. Bernie Sanders (I.-Vt.). These two have led full-scale opposition to Trump’s nominees, typified by Warren’s hashtag: #resist.

Had Schumer-Durbin maintained control of the Senate Democrats, they would have been able to certainly pick off Republican defectors to oppose Health and Human Services Secretary Thomas Price or Mnuchin, but that has not been the case. The intensity of the Warren-Sanders-led attacks on Trump’s nominees have driven Republicans away from the middle–and those Republicans not turned off by the attacks have been personally annoyed by Democrats insisting on every minute of the 30 hours of debate allotted for each nominee. The full debates have consumed so much time on the Senate floor that the only way to get the chamber flowing has been to keep the chamber open for days on end, conducting votes in the early morning hours.

As he did when he voted to confirm Attorney General Jeff Sessions, Sen. Joseph Manchin III (D.-W.V.) was the only Democrat to vote with Republicans when he voted to confirm Mnuchin. Manchin is a moderate Democrat up for reelction in 2018, who has reached out to the Trump White House looking for ways he can work with the president.

Hatch, while speaking on behalf of the Mnuchin nomination, touched upon the effect of the Democrats stretching out the process.

“People are free, I suppose, to walk into the confirmation process with an assumption of bad faith, but throughout my time in the Senate–and keep in mind, I’ve been here a long time–that isn’t usually how we operate around here,” he said.

“My colleagues on the other side have put forward a number of claims and allegations about Mr. Mnuchin–they’ve essentially thrown everything, including the kitchen sink,” he said.

But Senate Democrats are breaking with the tradition of treating certain departments, such as Treasury,to a non-partisan standard, he said. “The Senate has never left this much time to go without a secretary of state. In fact, the Senate has never left Treasury without a confirmed secretary for this long.”

Majority Leader Sen. Mitch McConnell (R.-Ky.) said the effort to keep the Senate going at all hours was also taking its toll on the Senate staff.

“It’s been really disappointing to see the historic level of obstruction by Senate Democrats,” he said.

“I’d like to remind our colleagues across the aisle of the very real consequences of their actions on our country and the men and women forced to work grueling house to keep the Senate running overnight.”

The Mnuchin vote was over by 7:30 p.m.