Presenting your 2018 Senate power rankings

**Want FOX News Halftime Report in your inbox every day? Sign up here.**

PRESENTING YOUR 2018 SENATE POWER RANKINGS
Please indulge us in cravenly putting our proviso first: The election is still ten months and a day away, so what you will see below is primordial in nature.

But, you have to start some place, even if it’s in the ooze.

The two main ideas to consider when examining the 2018 battle for control of the Senate are the narrowness of the current Republican majority – one seat – but also the extraordinary imbalance in the seats up for election – eight Republican-held seats to 27 Democrat-held seats.

It is only that imbalance that is keeping control of the Senate up in the air. The party of a first-term president going into midterms clinging to a single-seat majority would typically be already left for dead. In the modern era, it was only in 2002, in the wake of the September 11, 2001 terror attacks, that a first term president’s party actually gained Senate seats in midterms.

But chance and Democratic wave elections in 2006 and 2012 have conspired to give Republicans the kind of odds that even incumbents with an unpopular president could like.

You will see in the rankings below that we have included the filing dates by which perspective candidates must announce their intentions. These deadlines, now fast approaching, will tell us a great deal about which seats really are competitive. Take Florida, for example. We have classified the race as potentially competitive, but if Republican Gov. Rick Scott opts against challenging incumbent Sen. Bill Nelson, Republicans will see that one drift away on the Gulf Stream.

After candidate recruitment comes primaries. How bad the ranker, how expensive the campaigns and how good the final candidates are will, in several cases, be determinative – Arizona, for example.

If Republicans spend too much, fight too bitterly and still come up with a weak general election nominee in the demographically shifting Grand Canyon State, retiring Republican Sen. Jeff Flake will most likely be succeeded by a Democrat.

Now, most of the 35 races taking place this year will not be competitive. And if history is our guide, something more than 90 percent of the incumbents who are running will be returned to Washington.

The struggle for Republicans to defend or maybe even expand their narrow majority will come down to the fight for a smaller subset of races. We have identified 13 contests that appear to be either potentially competitive or, in some cases, guaranteed heavyweight brawls.

We will be revisiting this list throughout this election year and making adjustments as warranted. We will also be providing similar rankings for gubernatorial races, where Democrats hold a lopsided advantage, and the battle for control of the House, which promises to be a real donnybrook.

LIKELY REPUBLICAN 
Texas
Incumbent: Republican Ted Cruz, serving since 2013 
Candidate filing deadline: Already past 
Primary: March 6 (runoff May 22)
2016 presidential result: Trump, 53 percent; Clinton, 43 percent

Nebraska
Incumbent: Republican Deb Fischer, serving since 2013
Candidate filing deadline: March 1
Primary: May 15
2016 presidential result: Trump, 60 percent; Clinton, 34 percent

Mississippi
Incumbent: Republican Roger Wicker, serving since 2007
Candidate filing deadline: March 1
Primary: June 5 (runoff June 26)
2016 presidential result: Trump, 58 percent; Clinton, 40 percent
Potential candidates: State Sen. Chris McDaniel

Utah
Incumbent: Republican Orrin Hatch, serving since 1977 (retiring) 
Candidate filing deadline: March 15
Primary: June 26
2016 presidential election: Trump, 46 percent; Clinton, 28 percent

Wyoming
Incumbent: Republican John Barrasso, serving since 2007
Candidate filing deadline: June 1
Primary: Aug. 21
2016 presidential election: Trump, 70 percent; Clinton, 23 percent

LEANS REPUBLICAN 
Indiana 
Incumbent: Democrat Joe Donnelly, serving since 2013
Candidate filing deadline: Feb. 9
Primary: May 8
2016 presidential result: Trump, 57 percent; Clinton, 38 percent
Potential general election challengers: Rep. Luke Messer, Rep. Todd Rokita

Tennessee
Incumbent: Republican Bob Corker, serving since 2007 (retiring)
Candidate filing deadline: April 5
Primary: August 2
2016 presidential election: Trump, 61 percent; Clinton, 35 percent
Potential candidates: Rep. Marsha Blackburn (R), Rep. Stephen Fincher (R), former Gov. Phil Bredesen (D)

TOSS UP
West Virginia 
Incumbent: Democrat Joe Manchin, elected 2010
Candidate filing deadline: Jan. 27
Primary: May 8
2016 presidential result: Trump, 69 percent; Clinton, 27 percent
Potential general election challengers: Attorney General Patrick Morrisey, Rep. Evan Jenkins, Donald Blankenship

North Dakota 
Incumbent: Democrat Heidi Heitkamp, serving since 2013
Candidate filing deadline: April 9
Primary: June 12
2016 presidential election: Trump, 64 percent; Clinton, 28 percent
Potential general election challengers: Rep. Kevin Cramer, state Sen. Tom Campbell

Missouri
Incumbent: Democrat Claire McCaskill, serving since 2007
Candidate filing deadline: March 27
Primary: August 7
2016 presidential election: Trump, 57 percent; Clinton, 38 percent
Potential general election challengers: Attorney General Josh Hawley, Austin Petersen

Arizona
Incumbent: Republican Jeff Flake, serving since 2013 (Retiring)
Candidate filing deadline: May 30
Primary: Aug. 28
2016 presidential election: Trump, 50 percent; Clinton, 45 percent
Potential candidates: Rep. Kyrsten Sinema (D), Rep. Martha McSally (R), former state Sen. Kelli Ward (R)

Florida
Incumbent: Democrat Bill Nelson, serving since 2000
Candidate filing deadline: May 4
Primary: August 28
2016 presidential election: Trump, 49 percent; Clinton, 48 percent
Potential general election challengers: Gov. Rick Scott

LEAN DEMOCRAT 
Ohio
Incumbent: Democrat Sherrod Brown, serving since 2007
Candidate filing deadline: Feb. 7
Primary: May 8
2016 presidential result: Trump, 52 percent; Clinton, 44 percent
Potential general election challengers: State Treasurer Josh Mandel, Mike Gibbons

Pennsylvania 
Incumbent: Democrat Bob Casey Jr., serving since 2007
Candidate filing deadline: March 6
Primary: May 15
2016 presidential result: Trump, 49 percent; Clinton, 48 percent
Potential general election challengers: Rep. Lou Barletta

New Jersey 
Incumbent: Democrat Bob Menendez, serving since 2006
Candidate filing deadline: April 2
Primary: June 5
2016 presidential result: Clinton, 55 percent; Trump, 42 percent
Potential candidates: Rep. Frank Pallone (D), Rep. Donald Norcross (D), state Senate President Stephen Sweeney (D), Rep. Tom MacArthur (R), state Sen. Thomas Kean Jr. (R)

Montana
Incumbent: Democrat Jon Tester, serving since 2007
Candidate filing deadline: March 12
Primary: June 5
2016 presidential result: Trump, 57 percent; Clinton, 36 percent
Potential general election challengers: Auditor Matt Rosendale, state Sen. Albert Olszewski

Nevada 
Incumbent: Republican Dean Heller, serving since 2011
Candidate filing deadline: March 16
Primary: June 12
2016 presidential result: Clinton, 48 percent; Trump, 46 percent
Potential general election challengers: Rep. Jacky Rosen

Michigan 
Incumbent: Democrat Debbie Stabenow, serving since 2001
Candidate filing deadline: April 24
Primary: August 7
2016 presidential election: Trump, 48 percent; Clinton, 47 percent
Potential general election challengers: John James

LIKELY DEMOCRAT 
California 
Incumbent: Democrat Dianne Feinstein, serving since 1993
Candidate filing deadline: March 9
Primary: June 5
2016 presidential result: Clinton, 62 percent; Trump, 33 percent

New Mexico 
Incumbent: Democrat Martin Heinrich, serving since 2013
Candidate filing deadline: March 13
Primary: June 5
2016 presidential result: Clinton, 48 percent; Trump, 40 percent

Maine
Incumbent: Independent Angus King, serving since 2013
Candidate filing deadline: March 15
Primary: June 12
2016 presidential result: Clinton, 48 percent; Trump, 45 percent

Virginia 
Incumbent: Democrat Tim Kaine, serving since 2013
Primary: June 12
2016 presidential election: Clinton, 50 percent; Trump, 45 percent

Maryland 
Incumbent: Democrat Ben Cardin, serving since 2007
Candidate filing deadline: Feb. 27
Primary: June 26
2016 presidential election: Clinton, 61 percent; Trump, 35 percent

New York 
Incumbent: Democrat Kirsten Gillibrand, serving since 2009
Candidate filing deadline: April 12
Primary: June 26
2016 presidential election: Clinton, 59 percent; Trump, 38 percent

Washington 
Incumbent: Democrat Maria Cantwell, serving since 2001
Candidate filing deadline: May 18
Primary: August 7
2016 presidential election: Clinton, 54 percent; Trump, 38 percent

Hawaii 
Incumbent: Democrat Mazie Hirono, serving since 2013  
Candidate filing deadline: June 5
Primary: August 11
2016 presidential election: Clinton, 62 percent; Trump, 30 percent

Connecticut
Incumbent: Democrat Christopher Murphy, serving since 2013
Candidate filing deadline: June 12
Primary: August 14
2016 presidential election: Clinton, 55 percent; Trump, 41 percent

Minnesota
Incumbent: Democrat Amy Klobuchar, serving since 2007
Candidate filing deadline: June 5
Primary: August 14
2016 presidential election: Clinton, 47 percent; Trump, 45 percent

Minnesota (unexpired term)
Incumbent: Democrat Tina Smith, serving since 2018
Candidate filing deadline: June 5
Primary: August 14
2016 presidential election: Clinton, 47 percent; Trump, 45 percent

Vermont
Incumbent: Independent Bernie Sanders, serving since 2007 
Candidate filing deadline: May 31
Primary: August 14
2016 presidential election: Clinton, 61 percent; Trump, 33 percent

Wisconsin
Incumbent: Democrat Tammy Baldwin, serving since 2013 
Candidate filing deadline: June 1
Primary: August 14
2016 presidential election: Trump, 48 percent; Clinton, 47 percent

Delaware
Incumbent: Democrat Tom Carper, serving since 2001
Candidate filing deadline: July 10
Primary: Sept. 6
2016 presidential election: Clinton, 53 percent; Trump, 42 percent

Rhode Island 
Incumbent: Democrat Sheldon Whitehouse, serving since 2007
Candidate filing deadline: June 27
Primary: Sept. 11
2016 presidential election: Clinton, 55 percent; Trump, 40 percent

Massachusetts 
Incumbent: Democrat Elizabeth Warren, serving since 2013
Candidate filing deadline: June 5
Primary: Sept. 18
2016 presidential election: Clinton, 61 percent; Trump, 34 percent

Chris Stirewalt is the politics editor for Fox News. Brianna McClelland contributed to this report. Want FOX News Halftime Report in your inbox every day? Sign up here.