With the 2014 midterm elections less than two weeks away, Democrats are trying to fend off a strong Republican bid to take over the Senate, which could spell total gridlock for the remainder of Barack Obama's presidency. According to the latest FiveThirtyEight Senate forecast, 66 percent of the nation’s likely voters favor a GOP-controlled Senate. But Politico’s weekly ratings analysis suggests it’s still too close to call, with Democrats trailing closely behind Republicans 45 to 49 percent. And polls of national preferences have little meaning for individual state races, which many of the latest polls show effectively tied within the margins of error. Here are the latest readings on some of the top Senate races to watch:


A new CNN/ORC International poll has first-term Democratic Sen. Jeanne Shaheen, a former governor, and Republican challenger Scott Brown, a former senator from Massachusetts, in a close race within the margin of error. Shaheen has 49 percent of the vote, with Brown right behind at 47 percent and 3 percent undecided. The poll of 645 likely voters has a margin of error of 4 percentage points.


A Quinnipiac University poll released Thursday showed Republican state Sen. Joni Ernst “snout to snout” with Democratic U.S. Rep. Bruce Braley for retiring Democrat Tom Harkin's seat. Ernst tops Braley at 48 percent to 46 percent among likely voters, with 4 percent undecided. Quinnipiac University surveyed 964 likely voters with a margin of error of about 3 percentage points.


A SurveyUSA/11Alive News poll released Wednesday showed Democratic Senate hopeful Michelle Nunn would capture 46 percent of the vote, while GOP opponent David Perdue has 44 percent. Nunn has slowly gained ground over Perdue in the last six weeks, who has steadily yet slightly lost ground, according to the poll. Seven percent of the 606 likely voters polled said they were undecided. They are vying to succeed retiring GOP Sen. Saxby Chambliss. Nunn is the daughter of former Democratic Sen. Sam Nunn.


A USA Today/Suffolk University poll released Wednesday showed Republican Rep. Cory Gardner in the lead, after weeks of being statistically tied with first-term Democratic Sen. Mark Udall. Gardner is at 46 percent compared to Udall’s 39 percent, with a margin of error of about 4 percent either way. Although Gardner is just within the margin of error, at seven points, it’s his biggest lead this month. Nine percent remain undecided and 6 percent spread among the four independent and third-party candidates, according to the poll of 500 likely voters.


Democratic U.S. Sen. Kay Hagan holds a slim lead over Republican Thom Tillis, according to a SurveyUSA/WRAL News poll released Tuesday. Hagan, who is seeking a second six-year term, was favored by 46 percent of voters compared with 43 percent for Tillis, the speaker of the North Carolina House of Representatives. Libertarian candidate Sean Haugh holds 6 percent of the vote, while 5 percent were undecided. The poll surveyed 568 likely voters and has a margin of error of about 4 percentage points.


According to a Rasmussen Reports poll published Oct. 14, GOP challenger Dan Sullivan was leading by three points over incumbent Democratic Sen. Mark Begich. The poll of 700 likely voters showed Sullivan capturing 48 percent of the vote to Begich’s 45 percent, well within the poll’s margin of sampling error of 4 percentage points. Three percent of votes went to the other candidates and 3 percent were undecided.


The most recent poll released Oct. 6 from SurveyUSA/KOTA/KSFY/Aberdeen American News showed a three-way split among former Republican Gov. Mike Rounds, former Republican U.S. Sen. Larry Pressler, running as an independent, and Democrat Rick Weiland. Out of the 616 polled likely voters, Rounds had 35 percent, Pressler 32 percent and Weiland 28 percent, all of which are within the poll’s margin of error of four percentage points. They are competing for the seat of retiring Democrat Tim Johnson.