GOV. MARTIN O’MALLEY (D) unveiled his 2013 budget for Maryland the other day, accessorizing it with 38 pages of PowerPoint charts, graphs and talking points. The first slide pointed out that Maryland outstripped Virginia last year in job creation — a data point that has nothing to do with the state’s fiscal plan and everything to do with the Democratic governor’s personal rivalry with his Republican counterpart in the Old Dominion, Gov. Robert F. McDonnell (R).

Mr. O’Malley, in office since 2007, has proven a competent, hands-on and shrewd governor, and he figures in most lists of Democratic presidential prospects in 2016. He’s also ambitious and somewhat thin-skinned.

It must have rankled him when the Republican Governors Association, led by Mr. McDonnell, announced this month that it had hauled in a record $44 million for 2011, more than double the amount pulled in by the Democratic Governors Association, led by Mr. O’Malley. After all, Mr. McDonnell also appears on plenty of vice presidential and future presidential shortlists.

Payback time! In his budget presentation slide labeled “Jobs, Jobs, Jobs,” Mr. O’Malley trumpeted the 26,700 jobs added in Maryland through November, more than double the 10,900 in Virginia. It also noted that almost all Maryland’s new jobs were in the private sector, while most of Virginia’s were in the government.

Point to Mr. O’Malley, and a fair rebuttal to Virginia’s frequent crowing about its being a friendlier, lower-tax place to do business. But look more closely at the numbers, and Maryland’s glow starts to fade.

Since January 2010, when Mr. McDonnell took office, job growth in both states has been about the same, a little over 1 percent. Likewise, since the recession started in 2008, both states have lost jobs at roughly the same rate, slightly more than 3 percent.

And notwithstanding Mr. O’Malley’s one-year snapshot of job growth in 2011, Maryland’s unemployment rate, at a seasonally adjusted 6.9 percent, remains substantially higher than Virginia’s, which is 6.2 percent. In fact, while unemployment in Maryland has long been higher than Virginia’s, the gap is wider today than at any time since Mr. O’Malley took office, in 2007. Point to Mr. McDonnell.

Given the national epidemic of partisan rancor, the two governors have what counts these days as a cordial relationship, despite occasional jousting and more or less good-natured shots across the bow. Mr. McDonnell has described Mr. O’Malley as a “great Irish American.” Mr. O’Malley, whose temperament runs a little hotter, has been civil to Mr. McDonnell even as he’s attacked congressional Republicans. A friendly rivalry between the two provides an entertaining sideshow to 2012’s main event, and, possibly, a preview of what’s to come in 2016.