The top two primary rules in California has problems and this is a good example.

Can you write in a real democrat and maybe force a run off?

The main reason for this situation is that there was too much participation by the Democrats. The vote went mainly to 4 Democrats and the 2 Republicans who spent the most money. With the Democrats dividing their votes between 4 main candidates,the 2 Republicans totaled more votes than any of the Democrats. There could be a write in effort, but which of the several Democrats would the Democrats write in to surpass the Republican vote?

Someone in the party needs to step in and settle on one candidate to write in and then try to stick with this. Otherwise, the GOP will pick up this seat.

BTW, this is a classic example as to why the top two primary rules being used by California is a bad idea

There was a low voter turn out for a couple reasons. First there was no competition for Obama in the presidential race, so the result there was a foregone conclusion. Second, the district was new and completely different from the old district, so many of the names on the ballot were unfamiliar to many of the residents in the new district, consequently many of the voters just didn't know enough about the candidates to decide which one to vote for.

in 2014 the voters will realize what happened and get the person out.

If the law has not been changed by 2014, and there are not too many Democrat candidates, but there is the possibility that the Republicans will run several fake Democrats in order to divide the vote again.

Sorry to hear you have the greater of two evils to choose from.