Just over half of the Americans are satisfied with the current presidential choices, incumbent President Barack Obama or Republican challenger Mitt Romney, less than in any previous presidential campaign over the past two decades, according to a Pew survey released on Monday.

The latest national survey was conducted September 20 to 23 by the Pew Research Center for the People and the Press and the Washington Post.

The survey found 54 percent of Americans say they are either very or fairly satisfied with the choices on this year's campaign trail, while 40 percent say they are not too or not at all satisfied. The percentage expressing satisfaction with the candidates is lower than it has been in any election since 1992.

In September 2008, 72 percent of Americans said they were satisfied with the presidential choices that year. The 1996, 2000 and 2004 presidential campaigns also saw 61 percent, 64 percent and 66 percent respectively expressing satisfaction with candidates.

The latest survey, conducted among 1,005 adults, including 838 registered voters, also found that satisfaction ratings of the candidates are almost unchanged from June when 56 percent were satisfied with the presidential choices. Four years ago, satisfaction with the then presidential candidates rose from 60 percent in June to 72 percent in September.

Democratic voters continue to express more positive ratings of the candidates than Republicans. 66 percent of Democrats say they are either very or fairly satisfied with the presidential field this year, compared with 57 percent of Republicans and 45 percent of independents. In 2008, all three groups were more positive about the choices.