Crappy poll. Undecideds are too high or overestimated. I wouldn't be feeling relaxed if I were Boxer knowing I have only 46% support after being a senator for 18 years. The wave in the East could very much influence voters to turn out and support Fiorina and Whitman whereas they might have been disinclined to do so beforehand.
In CA, it's not uncommon to for a candidate to win with 40s numbers. Regardless, other polls have her at 50, so it's a moot point. Fiorina isn't getting enough crossover Democrats and has hit her ceiling. This one is done.