This is a collaborative knowledge base, feel free to propose edits/additions that you believe are important for others to know. Contributions will be reviewed and approved based on quality and accuracy.
On 1/12/2017, the Senate voted to pass the budget resolution 51-48 and on 1/13/2017 the House voted to pass the resolution 227-198 . Now, committees (which are smaller issue-focused groups that members of Congress are a part of) will have until January 27th to draft laws and pass them within the committees for consideration by all of Congress. The laws would specifically repeal elements of Obamacare.
On 1/5/2017, the Senate took the first procedural vote on a budget measure that would be used as a way for Republicans to repeal Obamacare through a process called Budget Reconciliation. The procedural vote passed 51-48, which will allow the Senate to consider the budget bill that includes the repeal of Obamacare. Republican Senators (and Republicans in the House) plan to hold a final vote on the budget resolution (that includes the Obamacare repeal) sometime before January 14. This budget bill will outline broad goals (i.e. cut $1 billion from the deficit over the next 10 years). Then, committees (which are smaller issue-focused groups that members of Congress are a part of) will have until January 27th to draft laws and pass it within the committees for consideration by all of Congress, the laws will specifically repeal elements of Obamacare.
Since a full repeal of Obamacare, also known as the Affordable Care Act, would need 60 votes in the Senate to overcome a Democratic filibuster , which is unlikely to happen, Republicans appear to have adopted a "repeal and delay" strategy focusing on repealing much of the law in Trump's first 100 days through Budget Reconciliation , making the repeal go into effect between 2019-2021 to give them time to pass a replacement (which they have not decided upon). This strategy of using Budget Reconciliation would only require 50 Senate votes to repeal much of Obamacare, though it would still take 60 votes to repeal all of Obamacare or to pass a replacement.  Using this approach, Republicans could eliminate Obamacare's Medicaid expansion, federal financial assistance for Marketplace coverage (premium tax credits and cost-sharing reductions), and individual and employer mandates.
They could not use this approach to eliminate the insurance market reforms (including the nongroup market’s guaranteed issue, the prohibition on excluding people with preexisting condition, modified community rating, essential health benefit requirements, and actuarial value standards). 
Repealing Obamacare through Budget Reconciliation would have the following impact:
- 29.8 million Americans will lose health insurance
- 82% will be working class
- 44% will be people of color
- Repeal will disproportionately impact Trump voters. 
- 3 million jobs will be lost by 2021.
- Obamacare exchanges may crash without an immediate replacement, even if the GOP follows though on its plan to include a delay on when the repeal goes into effect. 
- While there is no agreement in the GOP on a replacement plan, the plan proposed by Trump's Health and Human Services nominee, Tom Price, eliminates Medicaid coverage for 15,000,000 low-income Americans and allows insurers to discriminate against someone based on a pre-existing condition if they do not maintain "continuous coverage." 
- 55-64 year olds will see healthcare costs increase dramatically, even if healthy, by up to 10x and nearly 20% of people ages 55-64 could become uninsured.
- 2.8 million people with substance abuse issues will lose coverage.
- 1.25 million people with mental health issues will lose coverage, including many veterans.
- 71 million people, especially women, could lose access to free preventative services, including mammograms, immunizations, and affordable contraception (i.e. birth control).
- $350 billion will be added to deficit and $9 trillion added to debt, while the super wealthy (those with incomes above $1 million) will get a tax break of $57,000.
- Medicare Trust Fund, which was extended by a decade, will have several years reduced from its expected life.
Vulnerabilities in Their Strategy
There are currently 52 Republican US Senators. If all Democrats vote against a repeal, it will take at least 3 Republicans to join them to stop it from being passed.
- 4 Republican Senators - Lamar Alexander (Tennessee), Bob Corker (Tennessee), Tom Cotton (Arkansas), and Susan Collins (Maine) have expressed concerns  about repealing Obamacare without a replacement already worked out and 1 Republican Senator - Rand Paul (Kentucky) - has said he'll oppose legislation to repeal Obamacare because it increases federal deficit.
- According to FiveThirtyEight.com, the Republican Senators most likely  to oppose Trump are Susan Collins (Maine); John McCain (Arizona); Rand Paul (Kentucky); Rob Portman (Ohio); and Lisa Murkowski (Alaska).
- There are 20 Republican Senators currently representing states that have expanded Medicaid under Obamacare. Their states will be particularly impacted by a repeal and may be more willing to vote against it because a repeal might hurt their chances of reelection.
How You Can Resist
- Call your Senators and US House representative and tell them to vote against repealing Obamacare. You can call them at tel:(844)872-0234
- Call your Senators and tell them to vote against confirming Tom Price, who is strongly anti-Obamacare, to the Health and Human Services agency.
- Find out when your Senators and US Representative are holding town halls and other events (ribbon cutting ceremonies, etc.). Show up and tell them to vote against repealing Obamacare.
- Call your state legislators and local city council members and tell them to establish state- or city-based healthcare exchanges or single-payer models, as has been done in Massachusetts and San Francisco, and to pass legislation that taxes the wealthy to offset any Medicaid funding cuts and ensure low-income families keep their health insurance. You can use this tool to call them: https://embed.joincampaignzero.org/index.html