“Conservative” is not the right term to use to describe the Supreme Court Justices who have been the “conservative” majority in many 5 to 4 decisions going back to at least 2000. This applies in particular to the current five “conservative” justices who will be the deciding majority in many future decisions.
Chief Justice Roberts and Justices Alito, Gorsuch, Kavanaugh, and Thomas are probably better described as “radical, right-wing” justices. They could also be described as Republicans, small government ideologues, corporatists (supporters of large corporations and businesses), and/or plutocrats (supporters of the wealthy elites). Predecessors Rehnquist and Scalia also fit this mold; Kennedy, Souter, and O’Connor were a little harder to categorize.
These “conservative” justices are frequently making decisions that are not impartial decisions based on the law – despite their claims at confirmation hearings that they are just umpires calling balls and strikes based on the law (or some variation on this theme). One expert commentator states that “many of the Roberts Court’s decisions are so poorly reasoned that they appear to be straight-up dishonest.” (p. 52)  Despite nominees’ statements at confirmation hearings they respect precedents and established law (or something to that effect), their decisions frequently do not do so.
The “conservative” justices are also not strict constitutionalists – committed to following the original intent of those who wrote the Constitution and the Bill of Rights – despite their claims to be. Trying to apply laws and principles written back in the late 1700s to today’s world without interpretation and adjustment is ridiculous on the face of it, even if they did consistently try to do this (which they don’t). For example, corporations barely existed in the 1700s and they were nothing like the huge, multi-national corporations we have today. Also, the guns that existed then took many seconds, if not a minute or so to reload, while today we have guns that fire multiple bullets per second. Not to mention transportation and electronic communications that today happen at speeds that couldn’t have even been imagined in the 1700s, let alone the ability to store and have ready access to information on the scale we do today. Even if the relevant intent of those constitutional authors could be determined, there is no reason, over 200 years later, to give such deified status to their pronouncements.
And the “conservative” justices have sometimes made decisions that simply contradict reality, as in their decision to effectively overturn the Voting Rights Act. (See my previous post on that decision here.)
The Supreme Court, in the years since the Bush vs. Gore decision in 2000, has frequently ruled in ways that serve Republican partisan purposes, without apparent concern about overturning settled law or precedents, or violating their own stated principles.  In Bush vs. Gore, the Supreme Court ordered Florida to stop recounting ballots in the presidential election, when the recount might have shifted the victory from Republican George W. Bush to Democrat Al Gore. It overruled Florida’s Supreme Court and election officials despite the “conservative” justices’ frequently stated belief in “states’ rights,” which means that the states have the power to conduct their business, such as elections, without interference from federal authorities.
Other Supreme Court decisions that have clearly benefited Republican partisan interests and that were 5 to 4 decisions include: 
- Janus in 2018, which ruled that workers in a unionized workplace do not have to pay union dues even though the union is still required to represent and advocate for them in collective bargaining and in grievances. This is expected to result in a drop in union membership and in the financial resources available to unions. The Justices were well aware that unions register and mobilize more voters, particularly minorities, than any other organizations and that these voters tend to support Democratic candidates.
- Shelby County in 2013, which effectively overturned the Voting Rights Act and allowed Republican state governments and election officials to make it difficult for minorities, low-income citizens, and other Democratic-leaning voters to register and vote. (See my previous post on this decision here.) Without this decision and the voter suppression it allowed, Democrat Stacey Abrams and not Republican Brian Kemp would almost certainly have been elected Governor of Georgia in 2018, for example.
- Citizens United in 2010, which, along with other rulings, allows corporations and wealthy individuals to spend unlimited sums of money in our elections. This money clearly works to the benefit of Republicans and, in general, those who support the power and political influence of corporations and wealthy individuals in our political system and policy making.
- Vieth vs. Jubelirer in 2004, which ruled that gerrymandering of electoral districts to favor one party over the other is not unconstitutional. The great majority of such gerrymandering, and by far the most extreme partisan gerrymandering, has been done to favor Republicans. Absent partisan gerrymandering, Democrats would likely have 15 to 20 more seats in the U.S. House. (See my previous posts on gerrymandering here and here.)
Congress could act in all these cases (as well as others) to reverse the effects of the Supreme Court’s decisions by clarifying the legislative intent and goals of underlying laws. One clear example is the Court’s decision that gutted the effectiveness of the Voting Rights Act. This decision is considered by some to be one of the mostly egregiously reasoned cases of the Roberts court. (See my previous post on this case here.) Congress could reinstitute the Voting Rights Act’s control over states’ election practices by updating the criteria for identifying jurisdictions that would be subject to federal oversight. The proposed Voting Rights Advancement Act in Congress would do this. 
Congressional action to reverse these politically or ideologically driven decisions is not only possible, and would not only reverse harmful effects and overturn bad legal precedents, but would also send a message that power resides with the people and Congress, not with five, unelected “conservative” men. Even if legislation to reverse these decisions or their effects can only be passed by the House, it could potentially temper future Supreme Court decisions. At the least, it would highlight the harm and lack of impartiality behind these decisions.
A subsequent post will identify other Supreme Court decisions where congressional action could negate the effects of the Court’s rulings. Another future post will identify future Supreme Court decisions that should be closely watched to see if the partisan, rather than impartial, decision making continues.
 Millhiser, I., 2/13/19, “Not so Supreme? Congress actually has a lot of power, mostly unused, to rein in the Roberts Court by clarifying the intent of the law,” The American Prospect (https://prospect.org/article/not-so-supreme)
 Kuttner, R., 5/15/19, “Over to you, John Roberts,” The American Prospect Today (https://prospect.org/blog/on-tap)
 Meyerson, H., 4/23/19, “The GOP Justices: Republicans first, white guys second, Constitutionalists third,” The American Prospect Today (https://prospect.org/blog/on-tap?page=1)
 Millhiser, A., 2/13/19, see above