GOP Sen. Ted CruzRafael (Ted) Edward CruzFBI investigating alleged assault on Fort Bliss soldier at Afghan refugee camp The Memo: Biden's immigration problems reach crescendo in Del Rio Matthew McConaughey on potential political run: 'I'm measuring it' MORE's lead over Rep. Beto O'RourkeBeto O'RourkeMatthew McConaughey on potential political run: 'I'm measuring it' Anti-Greg Abbott TV ad pulled minutes before college football game: Lincoln Project O'Rourke prepping run for governor in Texas: report MORE (D) in the closely watched Texas Senate race has shrunk to 5 percentage points in a new poll.
Cruz is leading O'Rourke among likely voters, 51 to 46 percent, according to the Quinnipiac University Poll released Monday, with 3 percent of voters remaining undecided.
The narrow lead marks a tightening in the Senate race from an Oct. 11 Quinnipiac poll, which found Cruz leading O'Rourke by a 9-point margin, 54 to 45 percent.
Peter A. Brown, assistant director of the Quinnipiac University Poll, said in a statement that O'Rourke remained "within striking distance," but "time is running out" if he is going to overtake Cruz.
"Sen. Cruz is ahead due to his winning the 'gender gap.' He wins men 56 - 39 percent, while Representative O'Rourke can manage only a 52 - 45 percent edge among women," Brown added.
Only 2 percent of likely voters who said they have decided whom they will support in next week's midterm election told Quinnipiac that they could change their mind.
The new poll was conducted from Oct. 22 to 28 and includes surveys of 1,078 likely Texas voters. The poll has a margin of error of 3.5 percentage points.
Cruz's lead in the Quinnipiac poll is narrower than his 6-point lead in a RealClearPolitics average of recent polling.
Democrats face a narrow path in an increasingly uphill battle of winning back the Senate majority.
In addition to keeping 10 seats in states won by Trump, including some races in which Democratic incumbents are behind in the polls, they would need to pick up two seats currently held by a Republican senator.
Democrats have focused their efforts on winning seats in Arizona and Tennessee, where GOP Sens. Jeff FlakeJeffrey (Jeff) Lane FlakeBiden nominates former Sen. Tom Udall as New Zealand ambassador Biden to nominate Jane Hartley as UK ambassador: report The Hill's Morning Report - Presented by Goldman Sachs - Voting rights will be on '22, '24 ballots MORE (Ariz.) and Bob CorkerRobert (Bob) Phillips CorkerCheney set to be face of anti-Trump GOP How leaving Afghanistan cancels our post-9/11 use of force The unflappable Liz Cheney: Why Trump Republicans have struggled to crush her MORE (Tenn.) are retiring.
They are also hoping to defeat Sen. Dean HellerDean Arthur HellerTexas abortion law creates 2022 headache for GOP Heller won't say if Biden won election Ex-Sen. Dean Heller announces run for Nevada governor MORE (R-Nev.), who is the only Republican senator up for reelection in a state won by Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonDemocrats worry negative images are defining White House Heller won't say if Biden won election Whitmer trailing GOP challenger by 6 points in Michigan governor race: poll MORE in 2016.