US legal system explained

The legal wrangling in Florida has focused worldwide attention on the United States judicial system, as well as its electoral system. Legal action is being pursued in both federal and state courts - and it appears that the courts are likely to choose the next US president. BBC News Online guides you through the many-layered US legal maze.

The US is run under a federal system in which the federal, or central, government in Washington shares authority with state governments.

This model of shared powers defines the relationship between the federal and state courts.

There is the federal court system, an integrated system divided into numerous geographic units. In addition to this each state has its own court system.

Under this dual federal-state court structure, the Supreme Court is the final arbiter of law on the federal level, while the highest court of each state (usually called supreme courts) has the ultimate authority to interpret matters of the law in its state.

Federal courts:

When federal constitutional or statutory matters are involved, the federal courts have the power to decide whether state law violates federal law.

All eyes on the Florida Supreme Court

In the federal system, the lowest court is the district court. There are 94 US federal judicial districts, with at least one district court in each state. In the largest and most populated states, there are several districts.

Next level up is the federal appeals court. These courts are considered the workhorse of the federal court system because the majority of cases are resolved there. There are 12 circuits of federal appeals courts across the US.

The apex of the federal system is the US Supreme Court. This consists of nine appointed justices who hear and decide cases concerning federal or constitutional law.

State courts:

Each state has its own independent judicial system.

Most states have a three-tiered judicial system composed of district courts, appeal courts and the state supreme court.

Each state is divided into counties, towns or villages. Local governments, like their state counterparts, have their own court systems, which are presided over by local magistrates.

Relationship between the two:

The functioning of these systems is complicated by the fact that there are multiple sources of law, and courts of one system are often called upon to interpret and apply the laws of another jurisdiction. More than one court may also have jurisdiction over the same case.

The US Supreme Court does not necessarily take precedence over a state supreme court. It may be decided that the result of the presidential election is a federal matter and should be heard by the US Supreme and not by a state court.

However, legal experts say that the state rather than federal jurisdiction is likely to be crucial. So the Florida Supreme Court may be the final authority in all the legal wrangling and decide this election.

It may be significant that the Florida Supreme Court has seven judges, all of them political appointees. Six of them are Democrats appointed by the predecessor of the current Republican Governor Jeb Bush.