Republicans Focus on Defending Senate in Campaign's Last Week 

Republican campaigns took a defensive approach a week before elections to determine control of the U.S. Congress, with the party spending more to try to hold on to previously secure House seats and President Donald Trump preparing a six-day trip focused on Senate races.

The National Republican Congressional Committee on Tuesday launched a wave of ads targeting 14 House of Representatives races, including defenses of eight incumbents and four currently Republican-held seats whose current officeholders are not running in the Nov. 6 elections.

Trump's planned blitz of Senate battleground states, including Florida, Missouri and Tennessee, follows an NBC/Marist opinion poll showing the Democratic U.S. Senate candidate in Arizona taking a 6 percentage-point lead and a Quinnipiac University Poll showing Democrat Beto O'Rourke pulling closer to Republican Senator Ted Cruz in Texas.

A Reuters analysis of a trio of political forecasting groups showed the picture in the House brightening for Democrats.

Of 65 races seen as competitive or leaning against the incumbent party, the odds of a Democratic victory had increased in 48 as of Tuesday in the eyes of at least one of the three of political forecasting groups — Cook Political Report, Inside Elections and the University of Virginia's Center for Politics — according to the Reuters analysis.

Democrats would need a net gain of 23 seats in the House and two in the Senate to take majorities away from Trump's fellow Republicans, which would put them in position to oppose the president's legislative agenda. Opinion polls and political forecasters generally show Democrats having a strong chance of winning a House majority, with Republicans expected to keep control of the Senate.

Early voting

Early voting has surged nationwide, with eight states already recording more ballots cast ahead of Election Day than in all of 2014, the last midterm congressional election cycle, according to University of Florida researchers.

"Many voters are looking for someone who will be a check and not just a rubber stamp," said Mike Levin, Democratic candidate in California's 49th congressional district, which encompasses a wealthy suburban stretch between Los Angeles and San Diego.

Republican Darrell Issa currently represents the district but is not seeking re-election.

Until recently solidly Republican, the district has been trending Democratic in recent elections. Republican presidential candidate Mitt Romney won it by 6 percentage points in 2012, but Democrat Hillary Clinton won it by 7 percentage points in 2016, a swing of 13 percentage points. This year, opinion polls give Levin an edge over his Republican rival, Diane Harkey.

"We talk a lot about the need to have a check on this administration," Levin said in an interview at a campaign office in San Clemente.

The seat is among more than 40 that were held by Republicans who are not running for re-election, the highest number since at least 1930.

Safer districts

Republicans are focusing their efforts on conservative districts Trump won by double-digit margins in 2016, particularly in rural areas. That has allowed Democrats to gain ground in more racially diverse urban and suburban districts like the one Issa represents.

In conservative areas where Trump remains popular, from upstate New York to southern Illinois, several Republican incumbents said they saw the odds as moving in their favor.

They said their chances have been boosted by the bruising debate around Trump Supreme Court nominee Brett Kavanaugh, who was narrowly confirmed by the Senate after denying a sexual assault allegation.

Anger over his contentious, protest-marred confirmation hearings and sympathy among conservatives toward Kavanaugh have boosted the enthusiasm of the Republican base, particularly in rural areas, candidates and strategists said.