In 2010, Democrats held the majority in both the House and the Senate, giving them a significant amount of power to pass legislation. Despite the lack of support from the Republican party, Democrats were able to push through the Affordable Care Act, also known as Obamacare. This major overhaul to the healthcare system was achieved through the Democrats' majority in Congress. The ability to pass legislation without the support of the opposing party is a clear demonstration of the power that comes with having the majority in Congress.
However, it could be argued whether it was fair for Democrats to have passed this law without any support from Republicans. On one hand, the majority party is elected to make decisions and implement policies that they believe will benefit the country. On the other hand, it's important for laws to have broad support from both parties in order to ensure that they will be sustainable in the long term and will effectively serve the needs of all Americans. In my opinion, it would have been more fair and productive for Democrats to have engaged in more compromise and negotiation with Republicans in order to gain support for the Affordable Care Act