George C. Edwards III / Special to The Washington Post

Could Mitt Romney win the popular vote on Tuesday while President Barack Obama captures a majority of the 538 electoral votes and a return trip to the White House? Recent polling results have raised just that possibility, reminding Americans once again that we cast ballots, but we don’t elect presidents directly. That job falls to the Electoral College, a system which requires candidates to win states, not just votes.

It is a process that began as part of the original design of the U.S. Constitution. The system, lifted from the Holy Roman Empire in central Europe, was established as a compromise between election of the president by Congress and election by the people. Americans vote for the electors, who then vote for the president.

Let’s take a look at the main justifications for maintaining the Electoral College and see how they stand up to scrutiny.

1. The framers created the Electoral College to protect small states.

The delegates to the 1787 Constitutional Convention had a variety of reasons for settling on the Electoral College format, but protecting smaller states was not among them. Some delegates feared direct democracy, but that was only one factor in the debate.

Remember what the country looked like in 1787: The important division was between states that had slavery and those that didn’t, not between large and small states. A direct election for president did not sit well with most delegates from the slave states, which had large populations but far fewer eligible voters. They gravitated toward the college as a compromise because it was based on population. The convention had agreed to count each slave as three-fifths of a person for the purpose of calculating each state’s allotment of seats in Congress. For Virginia, which had the largest population among the original 13 states, that meant more clout in choosing the president.

The framers protected the interests of smaller states by creating the Senate, which gives each state two votes regardless of population.

2. The Electoral College ensures that the winner has broad support.

Supporters argue that the format prevents candidates from targeting specific groups and regions instead forcing them to seek votes across the country. But that’s not the way it has worked out in recent presidential contests. Generally, Republicans have tried to stitch together an electoral majority from the South, Southwest and Rocky Mountain states, while Democrats have relied on the large states on both coasts and the Midwest, leaving certain swing states (Florida) as perennial battlegrounds.

Any system of electing the president requires some version of broad support, but the Electoral College may do little to promote that goal. In 2000, George W. Bush lost the popular vote to Al Gore but won in the Electoral College. His victory came largely from his support among white men. He did not win majorities among women, blacks, Latinos, urbanites, the young, the old or those with less-than-average income. In short, Bush claimed the White House with the backing of one dominant group.

3. In direct elections, candidates would only campaign in large cities.

Under any system, candidates try to spend their time in places where they can reach the most voters. But in a direct election, with every vote counting equally, candidates might have an incentive to appeal to voters everywhere, not just those in swing states. Because the price of advertising is mainly a function of market size, it does not cost more to reach 10,000 voters in Wyoming than it does to reach 10,000 voters in New York or Los Angeles.

Making every vote count in every state could have other benefits. It would stimulate party-building efforts and increase turnout. People are more likely to cast a ballot if they think their vote matters.

4. The Electoral College preserves stability in our political system by discouraging third parties.

The college offers no guarantee of such “stability” — in fact, history suggests otherwise. The Republican Party was born as a third (or even fourth) party, and it quickly established itself as a major force in the 1856 and 1860 elections. In 1912, Teddy Roosevelt ran as a third-party nominee, and though he didn’t win, he easily bested his former party’s candidate, the Republican incumbent, William Howard Taft.

The Electoral College system gives a third-party candidate more opportunities to wreak havoc than a direct election does. Think about what could happen in a neck-and-neck contest: If a third-party nominee won enough states to prevent either major-party candidate from winning the 270 votes needed for a majority, the House of Representatives would decide the outcome. Each state delegation gets one vote; Vermont and Wyoming would count the same as Texas and New York.

In addition, under the Electoral College, a third party can tip the balance in a closely contested state. In 2000, Ralph Nader was accused of “siphoning” votes from Gore in Florida. Had Nader not run, Gore could have won the White House.

Direct elections, especially those without a runoff, prevent such problems. Coming in third or fourth would gain a party no leverage in the selection of the president.

5. Electors must vote for the presidential candidate who wins their state.

In practice, electors may vote for whomever they please, and on rare occasions, they do. In a tight election, such behavior might deny either candidate a majority and throw the election into the House.

The 2012 Electoral College

How the 538 electors are allocated to the states and the District of Columbia fluctuates with population changes. Each state’s current number:

Alabama 9

Alaska 3

Arizona 11

Arkansas 6

California 55

Colorado 9

Connecticut 7

Delaware 3

D.C. 3

Florida 29

Georgia 16

Hawaii 4

Idaho 4

Illinois 20

Indiana 11

Iowa 6

Kansas 6

Kentucky 8

Louisiana 8

Maine 4

Maryland 10

Massachusetts 11

Michigan 16

Minnesota 10

Mississippi 6

Missouri 10

Montana 3

Nebraska 5

Nevada 6

New Hampshire 4

New Jersey 14

New Mexico 5

New York 29

North Carolina 15

North Dakota 3

Ohio 18

Oklahoma 7

Oregon 7

Pennsylvania 20

Rhode Island 4

South Carolina 9

South Dakota 3

Tennessee 11

Texas 38

Utah 6

Vermont 3

Virginia 13

Washington 12

West Virginia 5

Wisconsin 10

Wyoming 3