It took National Republican Senatorial Committee Chairman John Cornyn (Texas) the better part of a day before he finally expressed his support for Delaware’s Republican nominee for Senate.

Tea party conservative Christine O’Donnell’s upset victory over Rep. Mike Castle in Tuesday night’s primary left national Republicans dazed. Her insurgent campaign could not be derailed in the days before the vote by the vocal efforts of party leaders, including Cornyn and Karl Rove, both of whom dismissed O’Donnell as unelectable in November.

They wanted Castle, who was favored to claim the seat for the GOP in the general election, and when he didn’t win, it took a while for the party to come around.

Finally, midday Wednesday, Cornyn said this: “I reached out to Christine this morning, and as I have conveyed to all of our nominees, I offered her my personal congratulations and let her know that she has our support,” Cornyn said in a statement. “This support includes a check for $42,000 — the maximum allowable donation that we have provided to all of our nominees — which the NRSC will send to her campaign today.”

It was widely reported Tuesday night that the NRSC would ignore O’Donnell, who is thought to have little appeal among the independents and Democrats who dominate the First State’s political landscape.

Cornyn did not rule out the possibility that the NRSC would make independent expenditures in the Delaware race, which is covered by the expensive Philadelphia media market. But he didn’t offer much hope to the cash-strapped O’Donnell campaign, which reported a little more than $20,000 in the bank as of Aug. 25.

Public Policy Polling released a survey Wednesday morning that showed O’Donnell well behind in a general election matchup with Democrat Chris Coons, although the poll was conducted before her upset victory on Tuesday.

Coons begins the contest with a 50 percent to 34 percent lead over O’Donnell, the survey from the Democratic firm found.

Castle led Coons, 45 percent to 35 percent, according to the survey of 958 likely Delaware voters taken Sept. 11-12.

PPP is the same firm that released a poll showing O’Donnell ahead of Castle in the days before Tuesday’s primary.

“A small group of Delaware Republicans most likely cost their party this seat and any chance at gaining control of the Senate last night,” said Dean Debnam, president of Public Policy Polling. “What has looked like an easy Republican win the entire cycle now looks like an easy one for the Democrats.”