When we learned last week that California Republican Congressman Duncan Hunter would be pleading guilty to various campaign finance fraud charges, we probably should have seen this coming. After insisting for many months that he was innocent and would remain in office while fighting to clear his name, he announced yesterday that he will be resigning shortly. (NBC News)

U.S. Rep. Duncan Hunter, R-Calif., announced Friday he plans to resign from Congress “shortly after the holidays,” just days after admitting to misusing campaign funds.

Hunter pleaded guilty in federal court Tuesday to one count of conspiracy to misuse campaign funds after prosecutors said he and his wife, Margaret, who pleaded guilty earlier this year to conspiracy to misuse campaign funds and was expected to testify against him, “converted and stole” more than a quarter-million dollars in campaign funds.

“Shortly after the Holidays I will resign from Congress,” Hunter said in a brief statement. “It has been an honor to serve the people of California’s 50th District, and I greatly appreciate the trust they have put in me over these last 11 years.”

It’s somewhat surprising that it took him three days to make the announcement. As soon as we learned that he was pleading guilty, the House GOP leadership warned Hunter that he should “refrain from voting” on the House floor. That’s not exactly a subtle hint. If Hunter didn’t resign soon, his own party would have been forced to vote to eject him from his seat, adding additional embarrassment to an already bad situation. (And the Democrats would have gone along with the plan happily.)

The court case wasn’t going to go well for Hunter if he decided to continue fighting it. We also learned this week that his wife (who already plead guilty to her part in the scheme as his campaign manager) was expected to testify against him as part of her deal. I suppose that’s only fair since he originally tried to blame the entire thing on her.

Both Hunter and his wife were looking at up to five years in prison for the misuse of campaign funds. Since she pleaded guilty early in the process and agreed to cooperate with prosecutors, the wife may wind up getting a relatively light sentence, possibly without serving any time. As for the Congressman, he fought the process for too long and made the prosecutors work the case. Also, as a member of Congress, the expectations were higher for him than a campaign staffer. With that in mind, don’t be surprised if Hunter winds up getting several years behind bars, if not the full five.

By waiting until January to resign, Hunter is giving Governor Gavin Newsom several options. Under state law, the Governor can either call for a special election, run a special election concurrent with the primary election in March, or leave the seat empty until the general election in November. That last option would rob the GOP of one extra vote for pretty much all of next year. Given that the House Republicans already in the minority, they need every vote they can muster. And since Hunter’s district remains solidly red, I have a feeling we can guess which option Newsom will go with here.