It was a busy political day in Northern Virginia Wednesday.

Newt Gingrich stands with his grandson Robert and his wife Callista, as he explains why he is suspending his campaign for the 2012 Republican presidential nomination during an event in Arlington, Va., May 2, 2012. (Larry Downing/Reuters)

Former House Speaker Newt Gingrich brought his 2012 presidential campaign to an end at an event in Arlington, while the presumed Republican nominee continued hunting for votes nearby.

Romney spoke at Exhibit Edge, a Chantilly-based company that builds trade show exhibits, where he criticized President Obama’s record on taxes and regulation.

Read our colleague Philip Rucker’s full report.

Romney will round out the day with a fundraiser and a private dinner attended by Gov. Bob McDonnell and Lt. Gov. Bill Bolling. On Thursday, he will join McDonnell at Crofton Industries in Portsmouth in the early afternoon.

Virginia Democrats questioned why U.S. Senate candidate George Allen was not campaigning with Romney, who he said he supported just last week.

“As Mitt Romney makes his case to Virginians today and tomorrow he will be joined by Governor Bob McDonnell, but not former Senator George Allen, who is refusing to campaign with him this week,’’ said Brian Moran, chairman of the Democratic Party of Virginia. “That refusal is a surprise considering their mutual appreciation for Paul Ryan’s budget plan, the anti-middle class cut, cap and balance pledge and federal ‘personhood’ legislation that could ban birth control.”

Romney’s visit, the first in Virginia since the nomination contest wrapped up, comes days before President Obama travels to Arlington to talk to students and to Richmond for a rally.