There has been lots of studies on this, and part of the issue is how do you get an honest rating of someone’s happiness?

Here is an (10 year old) article from Time about and how studies show it’s not an easy thing to judge.

Summary:

• Self-Reported Happiness: Conservatives often report higher levels of happiness compared to liberals.
• Research Studies: New studies indicate that conservatives may judge their lives and circumstances more positively than liberals.
• Emotional Language: Analysis of transcripts from Congress shows that liberals use more positive words than conservatives.
• Genuine Happiness: Studies on smiling intensity suggest liberals display more genuine happiness.
• Impact on Behavior: Conservatives have a more confident style of self-assessment, which might contribute to their reported happiness.

The research suggests that the way conservatives and liberals perceive and report their happiness might be influenced by their self-assessment styles.