It appears you’re referring to a situation where a Democratic senator, who previously helped Kamala Harris get into the Senate, has not yet given public support to her run for US presidency. Without more specific information, I can’t provide details on this particular senator’s reasoning. Endorsements in politics often come following careful consideration, including assessing the political climate, public sentiment, and personal alignments.
It’s also key to remember that lack of public endorsement doesn’t necessarily mean lack of support. The senator may be waiting for the right moment to announce his/her support or they might be providing support behind scenes. It’s always important to wait for direct statements from the individuals involved for accurate information.