Historically, the second midterm, when a president has been in office for six years, is the election in which voters vent their spleen against his political party.  So the recent decision by Tim Johnson in South Dakota not to seek re-election gives Republicans an excellent chance to gain control of the Senate after Obama's second midterm election in 2014.

The exception to the above rule was Clinton in 1998, but the economy was roaring then, and the impeachment of Clinton also caused many Democrats to rally to his side.  Bush in 2006 lost control of both houses of Congress as voters fed up with Republicans expressed their anger the only way they could: by voting for Democrats.

Although the left will try every way it can to blame the upcoming economic collapse on Republicans, that argument is very weak with average voters when Obama won re-election and Democrats gained seats in both houses of Congress.  The voters immune to facts are also the voters who are least likely to vote in a midterm election when Obama will not be on the ballot.

This means that Republicans ought to increase their numbers in the House of Representatives, do well in state races, and, if they gain six Senate seats, capture control of that house of Congress as well.  The Senate races typically depend less on the mood of the nation and more on which particular seats are up for re-election, as well as which candidates are retiring. 

There are only two Republican incumbents retiring: Chambliss in Georgia and Johanns in Nebraska.  Republicans carried both states in the 2008 and 2012 presidential elections.  These should be very safe seats.  Eleven Republican incumbents are seeking re-election in Wyoming, Idaho, Kansas, Oklahoma, Texas, Mississippi, Alabama, South Carolina, Tennessee, Kentucky, and Maine.  The first ten of those eleven states were also carried by Republicans in both the 2008 and 2012 presidential elections.  The only real prospect Democrats have for picking up a Republican seat in 2012 is to defeat Susan Collins in Maine. 

Democrats will be defending 21 seats.  In four states -- South Dakota, Arkansas, Mississippi, and Montana -- not only did Obama lose in 2008 and 2012, but Republicans control both houses of the state legislatures.  West Virginia's Rockefeller is retiring, and in this state, which Obama lost both times, Republicans are stronger than at any time in state history.  

In North Carolina, a freshman senator will run in a state which Romney carried and in which Republicans control all of state government.  In Virginia, Republicans lost both times to Obama but control most of state government and have a popular retiring Governor McDonnell, who almost certainly will run for, and likely win, that seat.  In Alaska, Begich, who beat Stevens in 2008 only because of horrifically improper behavior by federal prosecutors, will seek his second term in a state which Republicans control and which Republicans have carried in every presidential election since statehood except 1964 and 1992.

Republicans, in a normal year, would pick up eight seats and lose one (Collins in Maine).  But 2014 may not be a normal year.  If there is a strong Republican tide, then Democrats could lose seats in Colorado, New Mexico, Iowa (Harkin is retiring), and New Hampshire and hold on to Collins's seat in Maine.  Levin is retiring in Michigan, where Governor Snyder and his Republicans control state government.  Merkley, the Oregon freshman senator, barely beat Smith in 2008, and Oregon is competitive, as the 2010 results showed.  If Democrats lose one other race -- Franken in Minnesota or retiring Lautenberg's seat in New Jersey -- then Republicans will have enough seats for cloture in the Senate. 

This, with a comfortable House majority for Obama's last two years, would enable Republicans to place on Obama's desk their legislative actions for his signing or veto, and Republicans in the Senate could also block any more appointments of radicals to the federal bench. 

What might Republicans set on Obama's desk?  Anything popular which he is sure to veto to placate his base: cut federal salaries by 5% until the federal budget is balanced; open up all federal lands to energy development; abolish agencies like the Department of Education; cut taxes on small businesses and exempt them from ObamaCare and other onerous regulations.  The key is to win enough Senate seats to end filibusters and pass bills.  The configuration of the Senate races in 2014, along with the historical "second midterm" losses the president's party faces, makes this a real possibility.