Poll: Who would thrive depends on who wins in 2012

• Electorate predicts which groups will be winners, losers
• Investors are for Romney, the young and old are for Obama
• Small-business owners are right in the middle

WASHINGTON -- Exactly who would be better off over the next four years under a President Obama or a President Romney?

In a new USA TODAY/Gallup Poll, Americans express definite perceptions about what groups would thrive under which administration, providing a portrait of how each contender has been defined in the public's view. That question and others in the survey map the political landscape as the campaign heads into its final five weeks.

It is an electorate that is less engaged, less enthusiastic and less favorably inclined toward the candidates than at this point in recent presidential campaigns. It is also an electorate that confidently predicts the groups that will be winners and losers, depending on who prevails on Nov. 6.

The rich? By an overwhelming 55 percentage points, those surveyed say upper-income Americans would fare better if Republican challenger Mitt Romney wins.

The poor? By 36 points, they say low-income people would do better under Barack Obama.

And by 10 points, middle-income Americans are seen as doing better over the next four years if Obama wins a second term. That's important politically, since most Americans identify themselves as middle class. One of Romney's most critical tasks -- including at the candidates' first debate Wednesday in Denver -- is to persuade more middle-class voters that electing him would be good for them.

There is also a gender chasm. By double digits, Americans say women would be better off under an Obama presidency; men would be better off under a Romney presidency. Given that, it's hardly surprising that female voters nationwide and in some crucial swing states have boosted Obama while male voters are inclined to support Romney.

With one group, though, there seems to be a disconnect. Those 65 and older are the age group that most strongly backs Romney. But by 11 points, Americans say seniors would fare better over the next four years if Obama prevails.

In contrast, voters under 30 are Obama's best age group. By 13 points, Americans say young people will do better if the president wins a second term.

The decisive judgments on which groups would be winners in an Obama or Romney presidency are a sign of how sharply defined the two candidates have become. Investors would do better under Romney, those surveyed say by an overwhelming 41 points. Racial and ethnic minorities would do better under Obama, they say by an equally huge 42 points.

Only one group fell right in the middle: Small-business owners. By 47%-47%, those surveyed divided over whether they would do better under Obama or Romney. For the other nine groups named, Americans by double digits and well outside the survey's margin of error say they would fare better under one or the other.

The poll of 1,446 adults, taken Monday through Thursday, has a margin of error of +/- 3 percentage points.

Republicans have opened a big enthusiasm gap: 64% say they are more enthusiastic than usual about voting, compared to 48% of Democrats. In general, though, the results show an electorate that is less excited and less engaged than in recent presidential elections.

Democrats are less enthusiastic about voting than in 2008, although Republicans are a bit more enthusiastic. Fewer Democrats and Republicans say they have given a lot of thought to the election than they did in the falls of 2008 and 2004.

Romney's favorable rating is 47%, lower than that of any presidential candidate at this point in the past 20 years. Obama's favorable rating is better, at 55%, but still lower than that of six of the past 10 major-party nominees.

Only 13% say both Obama and Romney would be a good president. Four years ago, 25% felt that way about Obama and 2008 rival John McCain.