hands in each election. Due to gerrymandering, fewer than 10% of all House seats are contested in each election cycle. Over 90% of House members are reelected every two years, due to lack of electoral competition. Gerrymandering of the House, combined with the general deficiencies of the first-past-the-post voting system, and divisions inherent in the design of the Senate and of the Electoral College, result in a discrepancy between the percentage of popular support for various political parties and the actual level of the parties' representation. In particular, gerrymandering has been found to benefit the Republican Party more than it does the Democratic Party. State elections State law and state constitutions, controlled by state legislatures regulate elections at state level and local level. Various officials at state level are elected. Since the separation of powers applies to states as well as the federal government, state legislatures and the executive (the governor) are elected separately. Governors and lieutenant governors are elected in all states, in some states on a joint ticket and in some states separately, some separately in different electoral cycles. The governors of the territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the United States Virgin Islands are also elected. In some states, executive positions such as Attorney General and Secretary of State are also elected offices. All members of state legislatures and territorial jurisdiction legislatures are elected. In some states, members of the state supreme court and other members of the state judiciary are elected. Proposals to amend the state constitution are also placed on the ballot in some states. As a matter of convenience and cost saving, elections for many of these state and local offices are held at the same time as either the federal presidential or midterm elections. There are a handful of states, however, that instead hold their elections during odd-numbered "off years." Local elections At the local level, county and city government positions are usually filled by election, especially within the legislative branch. The extent to which offices in the executive or judicial branches are elected vary from county-to-county or city-to-city. Some examples of local elected positions include sheriffs at the county level and mayors and school board members at the city level. Like state elections, an election for a specific local office may be held at the same time as either the presidential, midterm, or off-year elections. Tribal