Since March, when we last handicapped the nation’s 36 gubernatorial races, the number of tossups has risen. But overall, Democrats still seem poised to gain a few seats this fall.

In this handicapping, we’re shifting the ratings in eight states -- four in Republicans’ direction and four toward Democrats. Those states, respectively, are Alabama, Maryland, Massachusetts and New Hampshire, and Arizona, Iowa, Ohio and Pennsylvania.

Our ratings categories are safe Republican, likely Republican, lean Republican, tossup, lean Democratic, likely Democratic and safe Democratic.

Most notably, Iowa and Ohio switched from lean Republican to tossup, placing the total number of tossups at nine.

The tossup category now includes five seats currently held by Republicans, compared to three held by Democrats. (There is one Independent-held tossup seat, which is occupied by Alaska Gov. Bill Walker.) The Republican-held tossup seats are in Florida, Iowa, Michigan, Nevada and Ohio. The Democratic-held tossup seats are in Colorado, Connecticut and Minnesota.

Meanwhile, Arizona’s race has also become competitive, shifting from likely Republican to lean Republican.

All told, the number of competitive races -- that is, those labeled lean Republican, tossup or lean Democratic -- has shrunk by two, from 18 at the end of March to 16 today.

Here’s the current breakdown of competitive races:

RATING D-HELD R-HELD I-HELD TOTAL Lean Republican 0 3 0 3 Tossup 3 5 1 9 Lean Democratic 1 3 0 4 Total 4 11 1 16

The three GOP-held seats that currently lean Democratic are in Illinois, Maine and New Mexico. By contrast, no Democratic-held seat leans Republican.

Overall, the GOP holds a 33-16 edge in gubernatorial offices and will have more seats to defend this year -- 26 to the Democrats’ nine.

In a neutral political environment, Democrats should be able to gain up to three governorships. But if the political winds prove to be in the Democrats’ favor, their net gain could be as high as five to seven seats. For the first time since 2006, the GOP will control the White House and Congress during a midterm election -- a balance of power that historically helps the party not in office.

For an interactive version of our ratings map, and the latest news in each race, click here.

Shifts Toward Republicans

The key Republican gains since March have been in three solidly blue states that have elected moderate Republican governors: Maryland, Massachusetts and New Hampshire.

In Massachusetts, which we’re shifting from likely Republican to safe Republican, Gov. Charlie Baker has a 30-point lead over potential rivals in recent polls.

In New Hampshire, Gov. Chris Sununu is up by about 20 points against Democrats in recent polls. We’ve shifted this race from lean Republican to likely Republican.

And in Maryland, Democrat Ben Jealous -- the more liberal of the top two finishers in the primary -- won the nomination to face Gov. Larry Hogan. That result, combined with Hogan’s strong approval ratings, has led us to move this race from lean Republican to likely Republican.

The final race to move in the Republican direction with this handicapping is Alabama. There, Gov. Kay Ivey won an impressive 56 percent of the vote in a contested primary, avoiding a runoff. That performance led us to shift this race from likely Republican to safe Republican.

Shifts Toward Democrats

For the Democrats, three of the shifts come in states where the party fared poorly in the 2016 presidential race: Iowa, Ohio and Pennsylvania.

In Iowa, there haven’t been any recent polls in the gubernatorial race, but in the Democratic primary, Fred Hubbell prevailed in a sizable field with an impressive 56 percent of the vote. And, according to the online publication Morning Consult, President Trump’s approval rating -- in a state he won -- has fallen sharply and is now “under water.”

In Ohio, Democrat Richard Cordray, the establishment favorite, won the nomination over former U.S. Rep. Dennis Kucinich. He leads the GOP nominee, Mike DeWine, in two of the three most recent polls. As with Iowa, voters in Ohio have soured on President Trump. He’s also under water in approval ratings there, according to Morning Consult.

We’re moving both of these states’ races from lean Republican to tossup.

Pennsylvania is another state that Trump won but where his popularity has slipped. Gov. Tom Wolf has been up by an average of about 15 points in recent polls against Republican nominee Scott Wagner. We’re moving this race from lean Democratic to likely Democratic.

Finally, the first independent poll of the race in Arizona, released in early July, shows Republican Gov. Doug Ducey in a dead heat with two Democratic hopefuls, David Garcia and Steve Farley. We’ve shifted this race from likely Republican to lean Republican.