Although presidential elections occur every 4 years, many people feel that they do not have a true understanding of how presidential campaigns operate.

The winner in the November general election is almost certain to be either the Republican or the Democratic nominee. A minor-party or independent candidate, such as George Wallace in 1968, John Anderson in 1980, or Ross Perot in 1992 and 1996, can draw votes away from the major-party nominees but stands almost no chance of defeating them.

A major-party nominee has the critical advantage of support from the party faithful. Earlier in the twentieth century, this support was so firm and steady that the victory of the stronger party's candidate was almost a certainty. Warren G. Harding accepted the 1920 Republican nomination at his Ohio home, stayed there throughout most of the campaign, and won a full victory simply because most of the voters of his time were Republicans. Party loyalty has declined in recent decades, but more than two-thirds of the nation's voters still identify themselves as Democrats or Republicans, and most of them support their party's presidential candidate. Even Democrat George McGovern, who had the lowest level of party support among recent nominees, was backed in 1972 by nearly 60 percent of his party's voters.

Presidential candidates act strategically. In deciding whether to pursue a course of action, they try to estimate its likely impact on the voters. During the 1992 campaign, a sign on the wall of Clinton's headquarters in Little Rock read, "The economy, Stupid." The slogan was the idea of James Carville, Clinton's chief strategist, and was meant as a reminder to the candidate and the staff to keep the campaign focused on the nation's slow-moving economy, which ultimately was the issue that defeated Bush. As in 1980, when Jimmy Carter lost to Ronald Reagan during tough economic times, the voters were motivated largely by a desire for change.

Candidates try to project a strong leadership image. Whether voters accept this image, however, depends more on external factors than on a candidate's personal characteristics. In 1991, after the Gulf War, bush's approval rating reached 91 percent, the highest level recorded since polling began in the 1930s. A year later, with the nation's economy in trouble, Bush's approval rating dropped below 40 percent. Bush tried to stir images of his strong leadership of the war, but voters remained concerned about the economy.

The candidates' strategies are shaped by many considerations, including the constitutional provision that each state shall have electoral votes equal in number to its representation in Congress. Each state thus gets two electoral votes for its Senate representation and a varying number of electoral votes depending on its House representation. Altogether, there are 538 electoral votes (including three for the District of Columbia, even though it has no voting representatives in Congress). To win the presidency, a candidate must receive at least 270 votes, an electoral majority.

Candidates are particularly concerned with winning the states which have the largest population, such as California (with 54 electoral votes), New York (33), Texas (32), Florida (25), Pensylvania (23), Illinois (22), and Ohio (21). Victory in the eleven largest states alone would provide an electoral majority, and presidential candidates therefore spend most of their time campaigning in those states. Clinton received only 43 percent of the popular vote in 1992, compared with Bush's 38 percent and Perot's 19 percent; but Clinton won in states that gave him an overwhelming 370 electoral votes, compared with 168 for Bush and none for Perot.

雖然總統競爭每四年舉行一次，但是許多人感到對競選大戰的運作沒有真正的理解。

11月份大選的獲勝者幾乎肯定是共和黨或民主黨的提名者。小黨派或獨立候選人，如1968年的喬治·華萊士，1980年的約翰·安德森或1992年和1996年的羅絲·佩羅，可能從大黨的提名人那里拉走了一些選票，但幾乎沒有人可能戰勝他們。

大黨提名人具有得到黨的忠實信徒支持這一關鍵的優勢。20世紀早期，這種支持是如此堅定、可靠，以至于較大黨派候選人的勝利幾乎是肯定的。華倫·G·哈定在俄亥俄州的家鄉接受了1920年共和黨的提名，并且在競選大戰大部分時間里都呆在俄亥俄。他大獲全勝只是因為當時投票的大部分是共和黨黨員。在近幾十年內，黨員對黨派的忠誠削弱了，但2/3強的國家的投票人依然認為他們自己是共和黨人或民主黨人，他們大多支持自己黨派的總統候選人。即使是近年來擁有最低水平黨派支持的民主人喬治·麥戈爾，在1972年仍得到了近60％本黨派投票人的支持。

總統候選人的行為頗講究策略。在決定是否遵循一項行動方針時，他們要盡量估計一下該方針對投票人可能具有的影響。在1992年競選大戰期間，小石城克林頓競選總部的墻上有一個牌子，上面寫著"經濟、蠢貨"。這條標語是克林頓的首席戰略詹姆斯·卡維爾的，主意，作為候選人和競選班子全體成員的警世語，使這場競選大戰集中在國家緩慢增漲的經濟上，這成為最后擊敗布什的策略。如同在1980年的經濟困難時期，吉米·卡特輸給了羅納德·里根，投票人的積極性主要來源于意圖改變的愿望。

候選人盡辦突出表現一種強有力的領導形象。然而，投票人是否接受這一形象，比起候選人的個人特點來更要依靠外部因素。在1991年海灣戰爭后，布什的支持率達到91％，這是本世紀30年代開始民意測驗以來的最高記錄。一年后，因國民經濟陷入困境，布什的支持率降低到40％以下。布什盡力去激起人們對他在戰爭時期強有力的領導形象的回憶，但投標票人依然關心經濟問題。

候選人的策略的形成要考慮到許多因素，包括憲法的這一條款：每個州具有的選舉人的票數與其在國會中的代表人數相同。因此，每個州因其參議院代表得到兩張選舉人票，依靠其眾議院代表得到不同數量的選舉人票。總共有538張選舉人票。要贏得總統職務，一個候選人必須得到選舉的多數票，即270張選票。

候選人特別關注是否能贏得人口最多的州，如加利福尼亞州（有54張選舉人票）、紐約州（33張）、得克薩斯州（32張）、佛羅里達州（25張）、賓夕法尼亞州（23張）、伊里諾伊斯州（22張）和俄亥俄州（21張）。僅在11個最大的州的勝利就可提供選舉的大多數，因此總統候選人在那些州花費大部分時間進行活動。1992年，克林頓只得到43％的大眾選票，相比之下布什得到38％，佩羅19％。但克林頓獲取支持的州給了壓倒優勢的370張選舉人票，相比之下給了布什168張，佩羅一張也沒有。