What's more, his campaign was fielding dozens of calls of support from top state Democrats and labor groups — many of whom had backed his leading opponent, state Sen. Rob Garagiola.
"We're going to win this seat," said Sen. Ben Cardin, who had remained neutral in the primary. He met with Delaney and state Democratic Party Chairwoman Yvette Lewis for lunch Wednesday in Montgomery County to discuss the November election. "The traditional friends of the Democratic Party will be there" in November, Cardin said.
Despite a bitter primary that split Democratic officials, including Gov. Martin O'Malley, who backed Garagiola, and Rep. Donna F. Edwards, who supported Delaney, party leaders were eager to present a show of unity as they prepared for an election that will be among the nation's most competitive.
Incumbent Rep. Roscoe G. Bartlett, a 10-term Republican who won his party's nomination Tuesday, said he also was readying for the next campaign. "If you want to continue this very liberal agenda, tax and spend, than you should vote for him," Bartlett said of Delaney. "That's what he's going to do."
The 6th District includes Western Maryland and portions of Frederick and Montgomery counties. The general election is Nov. 6.
Delaney's resounding victory Tuesday — he beat Garagiola by a nearly 2-1 margin — was an unexpected development in a story that began last year when lawmakers in the State House redrew the once reliably conservative district to make it more favorable to Democrats. Many of those lawmakers acknowledged that they had Garagiola, a rising star in Annapolis, in mind for the seat.
Delaney was able to deliver an unusual message to voters: As the head of CapitalSource, a Chevy Chase-based bank, he could credibly claim the mantle of "job creator," a label more often associated with Republicans. And he drove the message hard in both television and radio ads, outspending Garagiola by more than 3-1.
But on Wednesday, the primary seemed like a long time ago as both parties looked to the fall.
"We're all together in focusing on winning in November," Delaney said. "There's tremendous unity."
Senate President Thomas V. Mike Miller, a Garagiola ally who was an architect of the state's new congressional maps, said he would support Delaney. But Miller also raised questions about Delaney's wealth, suggesting that the banker should release his personal income tax returns.
The sentiment reprised an attack Garagiola had used during the primary.
"I would like to see him, now that the election is over, show his income taxes," Miller told reporters on the Senate floor. "That would be nice. We're all about disclosure and ethics. It would be nice to see if he pays less than 15 percent, less than Mitt Romney, or more."
Delaney has acknowledged that, like Republican presidential candidate Romney, he pays a lower federal tax rate on his income because much of it comes from investments. But he has also advocated raising that tax rate.
Other state Democrats hewed more closely to the prevailing message of the day.
"I will be doing everything in my power to help him ... be successful," said O'Malley, who had endorsed Garagiola last week. "He's going to be an outstanding standard-bearer for our party." Southern Maryland Rep. Steny H. Hoyer, the second-highest-ranking Democrat in the House, also rapidly moved to back Delaney, saying that he would do "everything I can to make sure he wins."
Closing ranks around the primary winner is something state leaders do as a matter of course, said Herbert C. Smith, a political science professor at McDaniel College in Westminster. Sometimes it isn't easy, but it's usually necessary to maximize support in the general election.
"It probably went on in Athens," Smith said jokingly.
In this case, he said, it should be easier to unite because even though the primary was bruising, Delaney's attacks focused mainly on Garagiola's record rather than veering into the personal. Delaney, Smith added, is an easy candidate for Democrats to get behind.
He "won big and he won fair," Smith said. "That makes the healing process more abbreviated."
One relationship that could prove more tricky to establish is between Delaney and the state's labor groups, virtually all of which backed Garagiola. A labor leader with United Auto Workers Local 171 had described Delaney as "dangerous to working families." Reminded of the statement, Delaney said he had spoken with labor leaders Wednesday and was confident they would play an important role in his campaign.
There were no overt signs of healing in the state Republican Party, meanwhile. Two GOP state lawmakers who lost to Bartlett in the primary had repeatedly raised questions about his electability as part of their campaigns. Republican officials said they were working behind the scenes to repair rifts.
Baltimore Sun reporters Annie Linskey and Michael Dresser contributed to this article.