Senate map 'historically difficult' for Dems, says pollster

Pollster Dan Cox in an interview that aired Tuesday on "What America's Thinking" said that the Senate midterm map for Democrats is "historically difficult" this year. 

"The map was never that favorable to Democrats to begin with," Cox, research director at the Public Religion Research Institute, told Hill.TV's Joe Concha. "It was a historically difficult map for them in places like Missouri, Arizona, North Dakota. They're trying to compete in places like Georgia and Texas, but those are kind of longshots."

"If you look at Texas, in particular, there has been so much tension on this race, but if you look at the polling, every statewide race, the Republican is leading," he continued. 

While Democrats appear to have a strong chance of taking back the majority in the House, Republicans appear poised to hold on to the Senate.

Democrats need 23 seats to regain control in the Lower Chamber and FiveThirtyEight.com gives them a nearly 86 percent chance of taking the House. But the Senate map provides a difficult challenge.

Democrats are defending Senate seats in ten states that President TrumpDonald John TrumpDC board rejects Trump Hotel effort to dismiss complaint seeking removal of liquor license on basis of Trump's 'character' DC board rejects Trump Hotel effort to dismiss complaint seeking removal of liquor license on basis of Trump's 'character' Mexico's immigration chief resigns amid US pressure over migrants MORE won in 2016 and already needed to pick up two more seats to gain the majority in the Upper Chamber. FiveThirtyEight.com gives the Democrats only a 16 percent chance to win the Senate.

Some closer Senate races have shifted to the right in recent weeks.

A Quinnipiac University poll released on Monday showed Sen. Ted CruzRafael (Ted) Edward CruzTed Cruz, AOC have it right on banning former members of Congress from becoming lobbyists Ted Cruz, AOC have it right on banning former members of Congress from becoming lobbyists Overnight Health Care: Democratic bill would require insurance to cover OTC birth control | House Dems vote to overturn ban on fetal tissue research | New rule aims to expand health choices for small businesses MORE (R-Texas) leading his opponent Rep. Beto O'RourkeBeto O'RourkeDemocratic presidential hopefuls react to debate placement Democratic presidential hopefuls react to debate placement Teachers union to host 2020 Democratic presidential forum focused on education MORE by five points in their race, while Republican Josh Hawley has a slim lead over Sen. Claire McCaskillClaire Conner McCaskillConservatives spark threat of bloody GOP primaries Congress needs to work to combat the poverty, abuse and neglect issues that children face Lobbying world MORE (D-Mo.) by an average of two points in Missouri's Senate race, according to Real Clear Politics.

RealClearPolitics average of polls also gives challenger Mike Braun (R) a slim edge in Indiana against Sen. Joe DonnellyJoseph (Joe) Simon DonnellyConservatives spark threat of bloody GOP primaries Anti-corruption group hits Congress for ignoring K Street, Capitol Hill 'revolving door' K Street giants scoop up coveted ex-lawmakers MORE (D).

— Julia Manchester