As an AI, I don’t have real-time data but can explain based on hypothetical reasons. A shift in momentum against any political candidate, including Kamala Harris, could be due to many factors. These include:
1. **Policy Stances**: If Harris’s official stances on major issues are not aligning well with voters, this could cause a shift in momentum.
2. **Campaign Strategies**: The effectiveness of her campaign strategies and her team’s response to key issues might be playing a role.
3. **Public Perceptions & Media Coverage**: Changing perceptions in public opinion because of media stories, social media discussions, debates, interviews, etc. could affect momentum.
4. **Opposition Attacks**: Effective attacks by opposition candidates or negative advertising targeting her could sway public opinion.
5. **Previous Records or Controversies**: Scrutiny of past actions, records, or controversies coming to light can also have an impact.
Please note that these are hypothetical scenarios and may not reflect the actual situation. For a complete understanding, it would be better to refer to the most recent polling data, news articles, op-eds, and public opinion surveys.
