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What Do We Know About the Security of Voting by Mail?

Mail-in voting has a long history in the U.S. In five states, vote-by-mail is the primary method of voting, and all states offer the option. Learn how these ballots are secured.


Why Can't We Vote by Phone or Online?

There is currently no online voting technology that can match the security and secrecy of in-person and mail-in voting.


How Do Election Officials Check for and Prevent Voter-registration Fraud?

One way election officials weed out errors and identify potential cases of registration fraud is through advanced data analysis using machine learning.


How Do Political Polls Work?

Polls help politicians, policymakers, researchers, and others gauge public opinion. Learn how polls are conducted and how to read a poll.


How Does Campaign Funding Work?

Find out who is allowed to donate to local and national political candidates and how public and small-dollar donations come into play.

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How Can Science Make Elections More Secure

Social and computer scientists provide data and observations that can help safeguard and strengthen electoral systems.

Read More >

Ask a Caltech Expert

Caltech researchers answer your questions: Why is it so hard to count every ballot? Why are presidential elections so difficult to forecast? And more.

Read More >

Terms to Know

In elections, a meeting of members of a political party to select candidates and elect convention delegates. Political parties in most states rely on primaries rather than caucuses to choose presidential nominees.

A person appointed or elected to represent others, including an elected representative responsible for voting for a presidential candidate at a party convention.

Taking away the right to vote from a person or group.

A survey of voters taken immediately after they exit their polling place to get an early indication of election results.

The formal body that elects the president and vice president of the United States. Each state has as many electors in the Electoral College as it has representatives and senators in Congress (the District of Columbia has three). Political parties in each state appoint a slate of electors, pledged to that party's candidate. Typically, the winner of the popular vote in each state determines which electors get to cast their votes. (That's why a candidate can lose the national popular vote but still win the presidency.) However, a number of states have joined an effort that would award electors to the winner of the national popular vote.

The independent regulatory agency charged with administering and enforcing federal campaign finance law.

The right to vote in public political elections. Also known as suffrage.

The political manipulation of voting district boundaries to benefit a particular group or party.

A statistical figure that indicates how much a polling result is likely to vary from reality.

Committees created by businesses, unions, trade associations, and membership groups that solicit contributions from employees or members in order to fund campaign spending. Unlike Super PACs, traditional PACs can donate directly to candidates. However, funds raised and spent by PACs are subject to federal limits.

In U.S. presidential elections, the popular vote refers to the number of all votes cast by voters from all states. The candidate who receives the most votes is the winner of the popular vote. Winning the popular vote does not amount to electoral victory. Although Americans cast a direct vote for a candidate of their choosing, states elect the president and vice president through the Electoral College. The winner of the Electoral College vote is not always the winner of the popular vote.

An election used to narrow the field of candidates for a given elective office or to determine the nominee for a political party ahead of a general election.

The process of dividing the 435 seats in the U.S. House of Representatives among the 50 states. Reapportionment occurs every 10 years based on population changes recorded in the United States census.

The process of defining electoral district boundaries. Districts are redrawn every 10 years following completion of the United States census. In 25 states, federal district boundaries are determined primarily by the state legislature, sometimes subject to approval by the governor. In other states, independent or bipartisan commissions are tasked with setting or proposing district boundaries. Redistricting also occurs at the state and local levels.

Like traditional PACS, super PACS are committees that raise funds to pay for campaign activities, such as advertising. Unlike traditional PACs, super PACs cannot directly contribute to or coordinate with campaigns or candidates. However, contributions to super PACs are not subject to federal limits.

Dive Deeper

Technology surrounding voting
Monitoring the Election: 2020 Voter Survey
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Can America Have a Safe and Secure Presidential Election?
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A Long March Toward Progress: A Conversation with Morgan Kousser