CARSON CITY, Nev. (AP) - U.S. Rep. Jon Porter, R-Nev., filed Monday for a fourth two-year term representing a suburban Las Vegas district that has been coveted by Democrats since its creation in 2001.

Porter filed for re-election with the Clark County registrar's office in Las Vegas, a day ahead of a scheduled filing by a strong Democratic challenger, state Senate Minority Leader Dina Titus, who ran unsuccessfully for governor in 2006.

The seat is on a short list of potential swing districts expected to draw national attention and dollars in November. Democrats also see the race as an opportunity to knock out a possible future rival to Senate Majority Leader Harry Reid. GOP leaders have urged Porter to run against the Nevada senator in 2010.

Titus got into the race after former Clark County prosecutor Robert Daskas, who had been the Democrats' top pick to challenge Porter, decided not to run, citing family considerations.

Daskas' fundraising had lagged, while Porter had more than $1 million cash on-hand at the end of the first quarter of the year while Daskas had about $450,000.

Voter registration numbers look promising for Democrats. The district, which includes parts of Las Vegas, Henderson and Boulder City, has historically had nearly equal numbers of Democrats and Republicans, but a massive Democratic voter registration push has shifted the balance in their favor.

(Copyright 2008 by The Associated Press. All Rights Reserved.)