A senate is a deliberative assembly, often the upper house or chamber of a legislature or parliament. There have been many such bodies in history, since senate means the assembly of the eldest and wiser members of the society and ruling class. Two of the first official senates were the Spartan Gerousia (Γερουσία) and the Roman Senate.

Many countries currently have an assembly named a senate, composed of senators who may be elected, appointed, have inherited the title, or gained membership by other methods, depending on the country. Modern senates typically serve to provide a chamber of "sober second thought" to consider legislation passed by a lower house, whose members are usually elected.

The modern word senate is derived from the Latin word senātus (senate), which comes from senex, "old man". The members or legislators of a senate are called senators. The Latin word senator was adopted into English with no change in spelling. Its meaning is derived from a very ancient form of simple social organization in which decision-making powers are reserved for the eldest men. For the same reason, the word senate is correctly used when referring to any powerful authority characteristically composed by the eldest members of a community, as a deliberative body of a faculty in an institution of higher learning is often called a senate. The original senate was the Roman Senate, which lasted until 580 (various efforts to revive it were made in Medieval Rome). In the Eastern Roman Empire, the Byzantine Senate continued until the Fourth Crusade, circa 1202–1204.

Randal Howard "Rand" Paul (born January 7, 1963) is the junior United States Senator for Kentucky. He is a member of the Republican Party. A member of the Tea Party movement, he describes himself as a "constitutional conservative" and a libertarian. He is the son of Republican Congressman and 2012 Republican presidential candidate Ron Paul of Texas and had never previously held political office. Paul first received national attention in 2008 when making political speeches on behalf of his father. Rand Paul is the first United States Senator in history to serve alongside a parent in the United States House of Representatives.

A graduate of the Duke University School of Medicine, Paul has been a practicing ophthalmologist in Bowling Green, Kentucky, since 1993, and established his own clinic in December 2007. In 1994, he founded Kentucky Taxpayers United, of which he is still the chairman.

In 2010, Paul ran as the Republican candidate for the United States Senate seat being vacated by retiring Senator Jim Bunning of Kentucky and defeated Kentucky Attorney General Jack Conway. As a supporter of the Tea Party movement, Paul has been vocal in advocating for term limits, a balanced budget amendment, and the Read the Bills Act, in addition to the widespread reduction of federal spending and taxation. He has gained prominence for his independent positions on many political issues, often clashing with both Republicans and Democrats.

John Forbes Kerry (born December 11, 1943) is the senior United States Senator from Massachusetts, the 10th most senior United States Senator and chairman of the Senate Foreign Relations Committee. He was the presidential nominee of the Democratic Party in the 2004 presidential election, but lost to then President George W. Bush.

The son of an Army Air Corps serviceman, Kerry was born in Aurora, Colorado. He attended boarding school in Massachusetts and New Hampshire and went on to graduate from Yale University class of 1966, where he majored in political science. He enlisted in the Naval Reserve in 1966 and, during 1968-1969, served a four-month tour of duty in South Vietnam as officer-in-charge (OIC) of a Swift Boat. For that service he was awarded several combat medals that include the Silver Star, Bronze Star, and three Purple Hearts. After returning to the United States, Kerry joined the Vietnam Veterans Against the War in which he served as a nationally recognized spokesperson and as an outspoken opponent of the Vietnam war. During that period, he appeared before the Senate Committee on Foreign Affairs where he deemed United States war policy in Vietnam to be the cause of "war crimes".

Rafael Edward Cruz, known as Ted Cruz (born December 22, 1970), is the former Solicitor General of the U.S. state of Texas, a position which he held from 2003 to May 2008. Cruz was appointed by Texas Attorney General Greg Abbott. He was the first Hispanic Solicitor General in Texas, the youngest Solicitor General in the United States, and had the longest tenure in the post thus far in Texas history. He is currently a partner at the law firm Morgan, Lewis & Bockius, where he leads the firm’s U.S. Supreme Court and national appellate litigation practice.

Cruz is a candidate for the 2012 Republican nomination for the United States Senate seat being vacated by Kay Bailey Hutchison.

Cruz previously served as the director of the Office of Policy Planning at the Federal Trade Commission, an Associate Deputy Attorney General at the United States Department of Justice, and as Domestic Policy Advisor to U.S. President George W. Bush on the 2000 Bush-Cheney campaign. In addition, from 2004-2009 Cruz was an Adjunct Professor of Law at the University of Texas School of Law in Austin, where he taught U.S. Supreme Court litigation.

Miriam Defensor Santiago (born Miriam Palma Defensor on June 15, 1945) is a Judge-elect of the International Criminal Court and a member of the Senate of the Philippines. She is a lawyer, former trial judge and professor of constitutional and international law. She served as the Commissioner of the Philippine Bureau of Immigration and Deportation in 1988 and the Secretary of the Philippines' Department of Agrarian Reform from 1989 to 1991. She is the founder and current leader of the center-right People's Reform Party allied with former president Gloria Macapagal-Arroyo, and is a Laureate of the Ramon Magsaysay Award for government service.

Defensor Santiago ran for President of the Philippines in 1992; she led the post-election canvass of votes for the first five days, but was ultimately defeated by a margin of less than a million votes out of 36 million votes. The campaign was reportedly marred by widespread election fraud, notably power blackouts after the first five days. She filed an electoral protest which was dismissed on a technicality in 1995 when she ran for and won a seat in the Philippine Senate.