State: Arizona
Type of election: Primary
How it works: This is a standard closed primary where only Arizona Republicans who were registered before January 30 will be able to vote. 29 delegates are at stake. There is no Democratic primary.
Official election results: Arizona Secretary of State
Republican candidates: Newt Gingrich, Ron Paul, Mitt Romney and Rick Santorum (all others have dropped out or are polling at less than 1 percent)
Previous performance: In 2008, Romney finished second to John McCain with 35 percent of the vote while Paul finished fourth with 4 percent. Barack Obama finished second to Hillary Clinton with 42 percent.
Newspapers: Arizona Republic, Phoenix New Times, full list
Television stations: Full list
Progressive blogs: Arizona Eagletarian, AZ Netroots, Democratic Diva, Friendly Fire, Random Musings, Rum, Romanism and Rebellion
Latest polling: New York Times:
Nate Silver gives Romney a 99 percent chance of winning.
Bottom line: Romney needs an easy win or two to maintain front-runner status and it looks like Arizona is going to give him one.
State: Michigan
Type of election: Primary
How it works: While technically, the primaries are closed, Michigan does not require voters to state their party when registering. On primary day, voters choose which ballot they wish to vote on in writing, and can only choose one party ballot. 30 delegates are at stake.
Official election results: Michigan Secretary of State
Republican candidates: Newt Gingrich, Ron Paul, Mitt Romney and Rick Santorum (all others have dropped out or are polling at less than 1 percent)
Democratic candidates: Barack Obama
Previous performance: In 2008, Romney won the Michigan primary with 39 percent, Paul finished fourth with 6 percent. Because of the early date of the primary, Obama withdrew from the primary and did not appear on the ballot.
Newspapers: Detroit Free Press, Detroit News, full list
Television stations: Full list
Progressive blogs: Michigan Liberal, Blogging for Michigan
Latest polling: New York Times:
Nate Silver gives Romney a 64 percent chance of winning and Santorum a 36 percent chance.
Bottom line: Silver understands the numbers better than I do, but this one really looks like a toss-up to me at this point. A Santorum win or close second means that nothing will be solved any time soon. A last place finish for Gingrich makes it hard to see how he can keep going much longer. As always, Paul is largely irrelevant.