By Marie Horrigan, CQ Staff

As election day draws closer, the prospects for Democratic gains in the House keep getting better.

And CQ Politics keeps changing our race ratings to reflect that.

Today, we’re changing the rating on two Nevada House seats: in the 2nd District, from to Republican favored to the more competitive Leans Republican and in the 3rd District from Leans Republican to No Clear Favorite, our most competitive category.

2nd District: Covering the entire state outside of Las Vegas and its suburbs, the 2nd is largely rural and has a conservative voting base that gave President Bush 57 percent of the vote in 2000 and 2004. But Democrats argue that a swing in voter registration rolls weakens the Republican hold on the district and makes the race more competitive than it might appear.

Jill Derby, a former member of the Nevada Board of Regents, is running against first-term Republican Rep. Dean Heller in a rematch of the 2006 race that Heller won 50 percent to 45 percent.

Derby resigned as state party chairwoman and got into the race in February after the Democrats struggled for months to recruit a candidate.

According to the candidates’ reports ahead of the primaries on Tuesday, Heller has raised $1.2 million for the race and had $1 million on hand by July 23 while Derby raised $465,000 and had $314,000 on hand by the same date.

Nonetheless, the Democratic Congressional Campaign Committee (DCCC) views the race as highly competitive. In June the committee added Derby to its list of “Emerging Races” that the party watches to see if candidates reach certain organizational and fundraising benchmark, and earlier this month the committee boosted Derby to its list of “Red to Blue” candidates that the committee helps directly.

Derby is running on a centrist agenda and was endorsed by the conservative Blue Dog Coalition, but Republicans maintain she is too liberal for the district. In a memo following Tuesday’s primaries, the National Republican Congressional Committee described Derby as “a true liberal Democrat . . . [who] would bring her reckless agenda to Washington.”

Democrats counter-charge that Heller has failed to vote in the interest of the district. “Congressman Heller has failed our veterans and repeatedly voted against measures that lower our gas prices,” Nevada Democratic Party Chairman Sam Lieberman said in a written statement.

3rd District: A late entry does not appear to be hampering Democrat Dina Titus from launching a strong campaign to unseat three-term GOP Rep. Jon Porter , who survived the 2006 challenge with less than 50 percent of the vote.

The 3rd District is a classic swing district that covers the suburbs of Las Vegas in Clark County. Democratic presidential nominee Al Gore carried the 3rd with 48 percent of the vote in 2000 while President Bush won with 50 percent of the vote in 2004. Since then, the Democrats have made voter registration gains that give the party the advantage in the 3rd District.

Titus entered the race in May after the party’s anointed candidate, former Clark County prosecutor Robert Daskas, dropped out for unspecified personal reasons. Democrats contend that despite entering the race only six months before Election Day, Titus presents a strong challenge. She is a more seasoned campaigner than Porter’s Democratic opponent in 2006, former congressional staffer Tessa Hafen. In 2006, Titus lost the Nevada gubernatorial election to Republican Jim Gibbons .