GALLUP NEWS SERVICE
PRINCETON, N.J. -- Gallup election polling trends suggest that the Republican Party can reliably be predicted to enjoy an increase in voter support for its presidential ticket over the course of the Republican convention next week in Philadelphia -- as can the Democratic Party next month in Los Angeles. Gallup polls going back to 1964 show that most presidential candidates enjoy an increase in the percentage of voters supporting them immediately after their national conventions, compared to polls conducted just prior to the event. While there has been wide variation in the size of this "bounce" in different years, the average bounce across the 18 Republican and Democratic conventions held since 1964 is roughly six percentage points. That average holds whether a convention is held first or second in a particular year, whether the candidate is an incumbent president or a challenger, and whether it is a Republican or Democratic convention.
Nineteen sixty-four is the starting point for Gallup's ability to measure this convention phenomenon. For most elections covered by Gallup prior to 1964, it is not possible to calculate a clear bounce due to either the close timing of the two conventions or to the infrequent rate of Gallup polling during the convention period.
Clinton's Record Bounce
The convention bounce surrounding Bill Clinton's 1992 bid for
president has taken on almost mythical proportions because of its
dramatic size. In mid-July of ‘92, Clinton entered the
Democratic convention period trailing George Bush by a 48% to 40%
margin, and emerged at the end leading by a 56% to 34% margin,
yielding a 16-percentage-point bounce for Clinton. This occurred,
however, under an unprecedented circumstance: Ross Perot (a strong
third-party candidate at the time) withdrew from the presidential
race on the last night of the Democratic convention, creating an
unusual political vacuum that Clinton was able to fill at the peak
of media coverage surrounding his convention. By contrast, George
Bush's bounce based on the Republican convention that year was much
closer to the historical norm, gaining just five points in voter
support (from 37% to 42%).
The next highest bounces in the Gallup records were both for Jimmy Carter. In 1980 Carter entered the Democratic convention with only 29% of the support of registered voters and left with 39% -- a 10-point bounce. This lifted Carter from second place behind Ronald Reagan to a tie for first place. Carter had a bounce of nearly the same magnitude in 1976, when he picked up nine points. Walter Mondale also picked up nine points in 1984 in his bid against Ronald Reagan.
However, according to Gallup records, most convention bounces have been more moderate in size, ranging from four to eight percentage points. There have been moderately high bounces of seven or eight points for three candidates since 1964: Michael Dukakis in 1988, Ronald Reagan in 1980 and Richard Nixon in 1972. Presidential candidates with average bounces of four to six points include Clinton in 1996, Bush in 1992 and 1988, Reagan in 1984, Gerald Ford in 1976, Nixon in 1968 and Barry Goldwater in 1964. Bob Dole in 1996, Hubert Humphrey in 1968 and Lyndon Johnson in 1964 received small bounces, on the order of just 2-3 points.
Only one of the last 18 conventions has failed to produce any bounce whatever for its standard-bearer: the fractious Democratic convention of 1972 that yielded no gain for George McGovern. In fact, his opponent, Richard Nixon, actually saw his share of the vote increase (from 53% to 56%) over the course of the Democratic convention.
Historical Bounce Statistics
The size of a candidate's convention bounce is not a precursor of
victory in November. On the contrary, two of the four candidates
who received particularly high increases as a result of their
conventions (Carter in 1980 and Mondale in 1984) subsequently lost
the election, and a third (Carter in 1976) barely won. Only
Clinton's large bounce in 1992 corresponded with a decisive victory
on Election Day.
Size of bounce also does not seem to be related to convention order. The average bounce for the candidates whose conventions came first each election has been almost seven percentage points, compared to roughly five points for those whose conventions came second. But if one excludes 1992 with Clinton's extraordinarily high bounce figures, that difference nearly disappears. On this basis, the average bounce since 1964 was about six points for all first conventions and about five-and-a-half points for second conventions.
History also suggests that in years when an incumbent president runs for re-election, he has been just as likely to benefit from a bounce as his challenger. Again excluding 1992, the average convention bounce for incumbent presidential candidates is roughly five-and-a-half points for both types of candidates.
Neither party appears to have an advantage when it comes to convention bounces, with the average being roughly the same for both. Across all eight presidential elections since 1964, the average convention bounce for Republicans has been just over five points and for Democrats it has been close to seven points. However, excluding 1992, the parties are virtually tied at roughly five-and-a-half points.
Bush Enters Convention with Slim Lead
The latest Gallup poll of likely voters shows George W. Bush
leading Al Gore in the race for president by just two percentage
points -- 48% to 46%. If Bush receives the average bounce as a
result of the convention coverage, including news of his
vice-presidential pick, the race could widen to as much as fourteen
points. However, the Democratic convention that follows can just as
reasonably be expected to reduce that lead. Receiving an average
bounce is of course no certainty for any given convention, which
means that a key election indicator this year will be the state of
the election as Labor Day approaches, after each convention has had
its opportunity to work its "bounce" magic.
|
Post-Convention Increases in Support, 1964-1996 |
||
|
Election |
Candidate |
Bounce |
|
1996 |
Bill Clinton |
5 points |
|
1996 |
Bob Dole |
3 points |
|
1992 |
Bill Clinton |
16 points |
|
1992 |
George Bush |
5 points |
|
1988 |
George Bush |
6 points |
|
1988 |
Michael Dukakis |
7 points |
|
1984 |
Ronald Reagan |
4 points |
|
1984 |
Walter Mondale |
9 points |
|
1980 |
Ronald Reagan |
8 points |
|
1980 |
Jimmy Carter |
10 points |
|
1976 |
Jimmy Carter |
9 points |
|
1976 |
Gerald Ford |
5 points |
|
1972 |
Richard Nixon |
7 points |
|
1972 |
George McGovern |
0 points |
|
1968 |
Richard Nixon |
5 points |
|
1968 |
Hubert Humphrey |
2 points |
|
1964 |
Lyndon Johnson |
2 points |
|
1964 |
Barry Goldwater |
5 points |
|
Convention Bounce Statistics, 1964-1996 |
||
|
Average Bounce Including 1992 |
Average Bounce Excluding 1992 |
|
|
All conventions |
6.1 points |
5.5 points |
|
Calendar Order |
||
|
First conventions |
6.9 points |
5.8 points |
|
Second conventions |
5.2 points |
5.3 points |
|
Political Party |
||
|
Republican conventions |
5.3 points |
5.4 points |
|
Democratic conventions |
6.8 points |
5.6 points |
|
Candidate Status |
||
|
Incumbents' conventions |
5.6 points |
5.7 points |
|
Challengers' conventions |
7.1 points |
5.7 points |
