Several broad outlines were proposed and debated, most notably James Madison's Virginia Plan and William Paterson's New Jersey Plan. The Virginia Plan was selected as the basis for the new government. While the concept of a federal government with three branches (legislative, executive, and judicial) and the general role of each branch was not heavily disputed, several issues delayed further progress and threatened the success of the convention. The most contentious disputes revolved around the composition and election of the Senate as the upper legislative house of a bicameral Congress; whether "proportional representation" was to be defined by a state's geography or by its population, and whether slaves were to be counted; whether to divide the executive power among three people or vest the power in a single chief executive to be called the President; how a president would be elected, for what term, and whether to limit each president to a single term; what offenses should be impeachable; the nature of a fugitive slave clause, and whether to allow the abolition of the slave trade; and whether judges should be chosen by the legislature or the executive. Most of the time during the convention was spent on deciding these issues.