A politician threatening to run as an independent can be a risky move for politicians, as it can alienate them from their base of support within the party. If they did leave their party, it can also be difficult for them as an independent candidate to win an election, as the two-party system in the United States typically gives an advantage to the Democratic and Republican candidates.

The impact of such a threat on voters can vary. Some voters may be more likely to support the politician if they feel that the politician is willing to take a stand and go against the party. However, others may see the threat as a sign of political opportunism and view the politician as less trustworthy. Additionally, some voters may see the threat as a sign that the politician is not committed to the party, which could lead to a loss of support.

Ultimately, the decision to run as an independent is a complex one that requires careful consideration of the potential benefits and risks. If you're interested in learning about independent politicians in the US, there are several books, publications, and documentaries that can provide insight into this topic. Here are a few suggestions:

Books:

• "The Independents: A Voter's Guide to Choosing Candidates for the White House and Congress" by Jaclyn Cashman and Andrew J. Bacevich - This book provides an overview of the independent movement in American politics and offers guidance on how to evaluate independent candidates.

• "Independent Politics: How American Disdain for Parties Leads to Political Inaction" by Samara Klar and Yanna Krupnikov - This book explores the reasons why some voters are drawn to independent politics and why others are skeptical of it.

• "Winning Elections in the 21st Century" by Dick Simpson - This book includes a chapter on independent candidates and their potential impact on elections.

Publications:

• "Independent Voter News" - This online publication provides news and analysis related to independent politics in the US.

• "The Nation" - The Nation has published articles on independent politics and candidates, such as "Could a Progressive Independent Win a Senate Seat in Maine?" by John Nichols.

• "HuffPost" - HuffPost has published several articles on independent politics, including "Bernie Sanders And The Long History Of American Independent Politics" by Zach Carter.

Documentaries:

• "The Independents" (2018) - This documentary profiles several independent candidates running for office in the 2018 midterm elections.

• "Run This Town" (2019) - A documentary that follows young independent mayors in America as they try to navigate their way through the political landscape.

• "Breaking the Chains" (2019) - A documentary that explores the independent political movement in Puerto Rico and its potential impact on the island's political future.

These resources can provide insight into the history and current state of independent politics in the US, as well as the challenges and opportunities facing independent candidates.

If you want to help make independent politicians more popular in the US, here are some actions you can take and organizations you can join or support:

• Educate yourself and others: The first step in promoting independent politicians is to educate yourself on the issues, the current political climate, and the various candidates and their platforms. You can then share this knowledge with others to help build support for independent candidates.

• Volunteer for an independent campaign: You can get involved in the political process by volunteering for an independent campaign. This can include helping with canvassing, phone banking, or social media outreach. You can also consider running for office yourself as an independent candidate.

• Join or support organizations that promote independent politics: There are several organizations that work to promote independent politics in the US, such as Independent Voting, Independent Voter Project, and Unite America. These organizations provide resources, training, and support to independent candidates and voters, and can help build a larger movement for independent politics.

• Encourage election reforms: One of the reasons that independent candidates often struggle to gain traction is due to the current election system, which can make it difficult for third-party candidates to get on the ballot or participate in debates. You can advocate for reforms such as ranked-choice voting, which can provide more opportunities for independent candidates to run and win.

• Support media outlets that cover independent politics: Independent media outlets such as The Intercept, The American Conservative, and The Young Turks often provide coverage of independent politicians and issues. By supporting these media outlets, you can help build a larger audience for independent politics.

By taking these actions and supporting these organizations, you can help make independent politicians more popular in the US and promote a more diverse and representative political system.