By Karl Rove
The theory is that states Obama won in 2012 are ripe for the plucking.

After sustaining crushing losses in 2014 Democrats are projecting confidence about recapturing the Senate in 2016. Unlike midterms according to the partys Senatorial Campaign Committee spokesman Justin Barasky a presidential election can only help Democrats." Count me skeptical.
To get a majority Democrats must defeat five of seven Republican senators in states President Obama won twiceFlorida Illinois Iowa New Hampshire Ohio Pennsylvania and Wisconsin. (Or five of eight Republicans if you add North Carolina which Mr. Obama won in 2008 but lost in 2012.)
The GOP took the Senate in 2014 by winning seven seats held by Democrats in states Mitt Romneycarried in 2012Alaska Arkansas Louisiana Montana North Carolina South Dakota and West Virginiaalong with seats in two states Mr. Obama carried Colorado and Iowa. So Democrats argue that if GOP Senate candidates can carry states that go Republican for the White House then Democratic Senate candidates are likely to carry states Democrats have won in presidential elections.
Although it is true that the Senate landscape in 2016 will be better for Democrats than last year there are flaws in their narrative.
First the states Republicans won in 2014 tilted far more Republican than the states with GOP incumbents up next year tilt Democrat. For example Republicans defeated incumbent Democrats in states Mitt Romney carried by 23.7 (Arkansas) 17.2 (Louisiana) 14 (Alaska) 5.4 (Colorado) and 2 (North Carolina).
By comparison Republican incumbents are up next year in states Mr. Obama generally carried by smaller margins namely 0.9 (Florida) 3 (Ohio) 5.4 (Pennsylvania) 5.6 (New Hampshire) 5.8 (Iowa) and 6.9 (Wisconsin). Only one GOP incumbent senator is in a state Mr. Obama carried by double digits: Illinois which he carried by 16.9.
Second it is hard to beat an incumbent. In the last eight presidential elections Democrats have defeated four or more Republican incumbent senators twice picking off five in 2000 and in 2008. It took extraordinary circumstances to pull this off. In 2000 President Clinton was unusually popular for a two-term incumbentand 2008 was a flat-out bad year for Republicans.
No one believes Mr. Obamas Gallup job-approval ratings will be close to the 57 Mr. Clinton enjoyed on Oct. 28 2000 right before that years presidential election. Mr. Obama last reached that level in December 2012 right after his re-election. Given the worlds trajectory his approval ratings next year are more likely to be lower than the 45 he received in this weeks Gallup poll.
Moreover seven of eight Republican senators in states Mr. Obama carried at least once are running for re-election. If the eighthFloridas Marco Rubiois in the hunt for the presidential nomination at the May 2016 filing deadline the GOP has two statewide elected officials Attorney General Pam Bondi and Chief Financial Officer Jeff Atwater in the wings.
Third Democrats are struggling to recruit Senate candidates. The only declared Democrat in Pennsylvania former congressman Joe Sestak announced without notifying national Democrats and is viewed skeptically by party leaders. Senate Minority Leader Harry Reid tried to clear the field in Ohio by endorsing defeated former Gov. Ted Strickland age 73 but failed.
The favored prospects in North Carolina and Wisconsin former Sens. Kay Hagan and Russ Feingold are spending this year teaching in Massachusetts and California respectively. New Hampshire Democratic Gov. Maggie Hassan is mum about running for the Senate but the legislature is shredding her budget and her idea to hire a chief operating officer for the state is being widely ridiculed. Several Democratic congressmen are considering running in Florida and Illinois raising the likelihood of expensive debilitating primaries.
Conversely not a single Republican seat in a red state looks at risk today. The only chance Democrats have to win these is if Republican incumbents draw serious primary challengers that divide the GOP.
The fourth problem for Democrats is they will be playing defense in at least two purple states: Nevada where Sen. Harry Reid had a 41 unfavorability rating in a Pew Research Center/USA Today poll late last year; and Colorado where a recent Quinnipiac poll found only 32 say Sen. Michael Bennet should be re-elected.
Finally each incumbent Republican senator is busy raising money building serious organizations and compiling a governing record that appeals to independents and Democrats so they run ahead of the GOP presidential candidate in their states.
The Democratic Senate campaign chairman Montana Sen. Jon Tester says I will not be successful in this job unless we take the majority back." Twenty-one months before the election Republicans are working hard to make Mr. Testers tenure unsuccessful.
A version of this article appeared March 12 2015 in the U.S. edition of The Wall Street Journal with the headline Democrats Are Bullish On Retaking The Senate and online at WSJ.com.