Elected Republicans like to talk a lot about "activist courts" overstepping their bounds to make decisions on public policy. Criticisms of "an activist court's 'social engineering'" are at least as old as Brown v. Board of Education and the desegregation of public schools. The same rhetoric has continued to the modern day, with conservatives griping about decisions in favor of same-sex marriage or the health care law.
But if you figured the party that claims to hate "judicial activism" would be opposed to using the courts to make or overturn democratically elected officials' policies, you would be dead wrong.
In fact, over the last several years congressional Republicans or Republican state attorney generals have sued the Obama administration or the man himself over executive orders in general, immigration policy, health care (multiple times), environmental protection, decades-old civil rights laws, and transgender rights.
In all of these cases the Republicans could have tried to pass a law to overturn executive actions, working within the democratic system. But in all cases they couldn't because Congress either couldn't pass anything or couldn't override a veto. So, rather than sticking to their own statements that the courts shouldn't overturn the laws, they turn to the courts to make or kill laws at every possible moment. They're even suing over a letter from the Department of Education that doesn't directly order states to do anything.
Since the Republican Party needs to control the courts to make policies that the people don't approve of, they've taken unprecedented steps to maintain their dominance. They've tried to block almost every single judicial appointment, leading to a historically overburdened and understaffed court system. Once they had a majority of the Senate they started refusing to even hold hearings on a Supreme Court appointee who their own membership has admitted is well-qualified.
The idea of maintaining the Supreme Court and the ability to make policies through it is so important to white Evangelicals that 84 percent of them will vote for a serial divorcé with almost no knowledge of the Bible on the hope that he nominates people very much unlike him.
If the party didn't resort to lawsuits the second they didn't get their way, I might be inclined to have a serious conversation about what role our judicial system should play. But they clearly don't mind the courts striking down policies they don't like. Judicial review, the right of the court to do so, was established in the very early days of American politics. They're even quite fine with courts trashing decades of precedent and common sense when it benefits them. So they can't seriously claim to be against "judicial activism" until they stop using it as a crutch.
What the Republican Party really hates is the government expanding the rights of minority groups. Some of the most prominent cases that get labeled "judicial activism" include desegregated public schools, desegregated publicly funded schools, expanded women's health care options, granted rights to LGBT people or upheld health care benefits for the poorest Americans. When the court rules in favor of the wealthy, big business or against civil rights laws, the Republican Party doesn't complain, however unprecedented the ruling is.
The fact is, we need the Supreme Court as both an interpreter of the Constitution and of common sense. To do that the courts need to be able to strike down unconstitutional policies or make rulings that don't seriously damage the fabric of American society. This has been acknowledged for more than a century by both parties. When the Republicans talk about hating "activist courts," they just mean the courts that care about vulnerable people and won't blindly sign off on agendas of oppression.