A poll conducted by outside groups aligned with the Democratic Party shows freshman Rep. Francisco (Quico) Canseco, R-Texas, trailing Democratic state Rep. Pete Gallego in a close campaign for Texas's 23rd Congressional District.

Gallego holds a narrow lead over Canseco, 43 percent to 38 percent, with the remainder of the electorate undecided, in a survey released on Tuesday and conducted for the League of Conservation Voters and the Sierra Club. The LCV endorsed Gallego and spent on his behalf during his primary, including running television ads.

The survey was conducted Sept. 12-17 by Anzalone Liszt Research, which interviewed 500 likely voters in English and Spanish. The poll has a margin of error of plus or minus 4.4 percentage points.

President Obama and Mitt Romney are deadlocked in the presidential ballot test in the district, with Obama at 46 percent and Romney at 45 percent. Obama won 49.7 percent of the 23rd District's presidential vote against John McCain in 2008, outpacing the Republican by a few tenths of a percentage point.

Both national party committees are already spending heavily in the district. The most recent filings with the Federal Election Commission indicate that the Democratic Congressional Campaign Committee has spent more than $260,000 attacking Canseco on television, while the National Republican Congressional Committee has spent more than $320,000 going after Gallego.

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