Hueso, 44, was stopped at 2:24 a.m. by CHP officers who spotted him driving the wrong way on a one-way street, 15th Street near the state Capitol, CHP Officer Julie Powell said.
Hueso was driving a state car, a white Ford Fusion at the time, she said.
"The officers observed objective signs and symptoms of alcohol intoxication," Powell said, adding that a subsequent field investigation determined that Hueso was under the influence of alcohol and "unable to safely operate the vehicle."
Hueso was taken into custody by the officers and booked into Sacramento County Jail at 3:27 a.m., county records indicate. He faces two possible misdemeanor charges, including driving with a blood alcohol level of 0.08 or more. Bail was set at $1,482.
Earlier in the evening, he had attended a reception by the Latino Legislative Caucus for members who are leaving office this year. A photo from the event at Il Fornaio restaurant showed what appeared to be wine on the table.
Another photo, time-stamped at 11:19 p.m., was posted on Twitter by Assemblywoman Lorena Gonzalez (D-San Diego) and shows Hueso with other senators at the Capitol, his shirt untucked and a glass in his hand as they all appeared to be singing. "Yes, Loving My Latino Caucus Boys," is the caption on the photo.
Sen. Hueso issued a statement apologizing for his behavior.
"I am truly and profoundly sorry for the unacceptably poor personal judgment which I demonstrated last night," Hueso said. "As someone who cares deeply about the public safety, I sincerely apologize to my family, my constituents and my colleagues in the Senate for breaching the trust they've all placed in me."
Hueso said he accepts personal responsibility for his actions and any punishments that occur. "I will also engage in immediate, corrective actions to ensure this kind of personal conduct is never repeated," Hueso said.
Senate President Pro Tem
"Obviously my reaction to the events of the prior evening is extreme disappointment," Steinberg said. "It's a lapse of personal judgment and I'm only glad that no one was hurt."
Steinberg said the Senate would not allow its members to use a balcony for drinking alcohol and he raised his eyebrows over the drinking at the Assembly speaker's balcony.
"The picture speaks for itself," Steinberg said. "The whole situation, I'm not happy about."
Hueso's arrest could complicate Democratic efforts to push through key legislation given that another senator, Loni Hancock (D-Berkeley), has been on home leave because of a broken leg and three other Democratic senators were suspended in March because of criminal charges.
Hueso was elected to the Senate in March 2013 and represents a district in San Diego County. He formerly served in the Assembly.
He chairs the Veterans Affairs Committee and the Select Committee on California's Energy Independence.
Before his election to state office, Hueso served on the San Diego City Council and the California Coastal Commission.