Supporters of a higher minimum wage rally in Illinois this October. (AP Photo/Seth Perlman)

Four states have minimum-wage increases on the ballot on Tuesday, an occasion that's notable for two reasons. All four states — Alaska, Arkansas, Nebraska and South Dakota — lean conservative, meaning that the debate over low wages and income inequality has spread beyond reliably blue parts of the country. And should these four measures pass, as they're all expected to, a majority of states in the U.S. will soon have higher wage floors than the federal minimum.

Something similar happened in the mid 2000s, right before mounting national pressure led Washington to act the last time. In 2007, when Congress last increased the federal minimum wage, 29 states and the District of Columbia guaranteed higher minimum wages than the federal rate of $5.15. As the national rate then gradually increased from $5.85 to $6.55 to $7.25 in the summer of 2009, the number of states out-doing the feds predictably fell:


Wage rates are as of Jan. 1 of each year. State rates reflect the highest minimum required, where states set a range of minimums for different occupations or employer sizes.

If state laws are a commentary on the absence of action in Washington, it's becoming clear once again that Congress is lagging behind public sentiment on the minimum wage. Alaska already has a minimum slightly higher than the federal one and would be raising it even more over the next two years, from $7.75 to $9.75. Arkansas, Nebraska and South Dakota, however, would bring the new total of states offering better than the federal minimum to 26, plus the District of Columbia.

Going into Tuesday, the national map looks like this:

As more and more states conclude that the federal minimum wage is insufficient, it will only get harder for Congress to hold the line at $7.25.