If no candidate wins more than 50 percent of the vote, a runoff between the top two vote-getters will be May 14.
The vacancy was created when Democrat Gloria Negrete McLeod resigned to be in the House of Representatives. She defeated Rep. Joe Baca in November.
Assemblywoman Norma Torres, D-Ontario, San Bernardino County Auditor-Controller Larry Walker, also a Democrat, as well as Pomona Planning Commissioner Kenny Coble have indicated they would seek to succeed Negrete McLeod.
"You know March 12 is just around the corner," said Torres, a former Pomona mayor who has been endorsed by the California Latino Legislative Caucus.
"I'm excited about the campaign. It's very fast paced. Everybody has to hit the pavement running and, as far as me, I'm very excited about the opportunity ... I think it's a very interesting field of people that want to represent the 32nd Senatorial District and I think I'm very well positioned and very qualified for this position."
Ontario Mayor Paul Leon and former Assemblywoman Wilmer Amina Carter, D-Rialto, have also showed an interest in running for the seat.
"First of all, I'm glad it's finally set. We were kind of waiting in limbo, but I think it's going to be fast and furious and we are all jumping out of the block running," Leon said.
"It's going to be a long running, drawn out campaign and I'm ready for it because I'm in shape and I'm ready.
Coble was defeated by Torres in November to represent the 52nd Assembly District.
"I am excited about this election," Coble said.
"This a very different election than the past general election. I am ready for this and serving our communities and state ... What we need now is not someone after the badge. But someone like me that is willing to do the job fully and as a statesman not a politician."
Walker, a former mayor of Chino and San Bernardino County supervisor, has been endorsed by Supervisors Josie Gonzales and Janice Rutherford.
"It's a very short time frame needed to fill the seat and get back to representing the people. I've prepared for it and I'm looking forward to the campaign," Walker said.
"At this point, I'm focused on my campaign so I'm working hard to raise funds and working hard to reach out to folks, and I've done that in various capacities over the years. Both these efforts have been very positive at this stage."
The 32nd State Senate District encompasses Pomona, Colton, Fontana, Montclair, Ontario, Rialto, San Bernardino and part of Chino as well as the unincorporated communities of Bloomington and Muscoy.
Reach Neil via email, call him at 909-483-9356, or find him on Twitter @InlandGov.