Commerce Clause
This line (Article I, Section 8, Clause 3) in the Constitution gives Congress power "to regulate commerce with foreign nations, among the several states and with Indian tribes." It governs more than just the exchange of goods and services for money. It is also the basis by which Congress enacts social policy involving environmental, criminal and civil rights laws, and senators will likely ask about the candidate's views on it.

Doctrinal
Method of constitutional interpretation that involves applying rules generated from precedent, i.e., previous court decisions.

Ethical
Method of constitutional interpretation based on perceived moral commitments and principals inherent in the Constitution.

Judicial Activism
Describes judges who create rights not explicitly stated in the Constitution or overturn laws they deem are unfair. Often used to describe liberal judges, but conservatives practice it, too.

Judicial Review
Principle established by the Supreme Court in 1803 that allows the court to strike down laws it deems unconstitutional.

Judiciary Committee
Senate committee charged with weighing a presidential nominee to the Supreme Court, as well as all other nominees to the federal bench, and making a recommendation to the whole Senate as to whether the nominee should be confirmed.

Living Document
The idea that the Constitution and its meaning grows and changes as society changes.

Original Intent
A philosophy of Constitutional interpretation based on an attempt to understand the intent of the authors of the Constitution when they wrote and adopted it.

Originalist
One who bases interpretation of the Constitution on the original meaning of the words in the document.

Precedent
Past decisions by the Supreme Court and other benches that form the established judicial thinking on a given subject.

Prudential
Method of constitutional interpretation that involves weighing the costs and benefits of laws and policies to society as a whole.

Stare Decisis
Latin for "let the decision stand." The ideas that previously decided Supreme Court cases set binding precedents that are considered law.

Strict Constructionist
One who strictly interprets the Constitution as it was written.

Structural
Method of constitutional interpretation based on rules determined by relationships between the branches of government as mandated in the Constitution.

Textual
Method of constitutional interpretation based on the text as it would be interpreted by a reasonable person.

-- Compiled from the Oxford Companion to the Supreme Court of the United States, the Associated Press and other media sources