Final answer:
Justice Souter's moderate-to-liberal stance meant his resignation could have shifted the balance of the Supreme Court. His absence potentially influenced the closely split 5-4 decision in the Citizens United case, which determined campaign contributions as protected speech under the First Amendment.
Step-by-step explanation:
The resignation of Justice Souter and the ensuing appointment of his successor had implications on many Supreme Court decisions, including the Citizens United case. Justice Souter was known for his moderate-to-liberal stance, and his departure from the Court shifted the balance, potentially affecting the outcome of closely split decisions.
The Citizens United decision, which ruled that the government cannot limit corporate political spending, was decided by a narrow 5-4 vote. The majority opined that campaign contributions were a form of speech, protected under the First Amendment. Critics and proponents fiercely debated the verdict, with opponents arguing it undermines the rule of law and could lead to political corruption.
President Obama notably criticized the decision during his 2010 State of the Union address, highlighting the deep divide and the significant impact of the ruling. Considering Justice Souter's perspectives, his absence may have influenced the tight margin of the decision, although it is not certain. Nonetheless, Justice Souter's resignation remains a pivotal moment that shaped the composition and subsequent decisions of the Supreme Court, including its controversial ruling on Citizens United.