National Harbor, a 300-acre development on the banks of the Potomac River. (Peter Fellows)

Miller’s comments came a day after Prince George’s Executive Rushern L. Baker II (D) announced his support for a billion-dollar casino on the banks of the Potomac River at National Harbor.

“I would prefer competitive bidding and choice,” Miller said in an interview. “Both sites have different positives. ... I personally don’t have a preference. I just want the county executive to weigh in after all the facts are known.”

A bill pending in the Senate would invite bids from locations within a small swath of western Prince George’s that includes both National Harbor, a dining, shopping and conference development; and Rosecroft Raceway, the recently reopened horse track in Forth Washington.

Baker’s preference was included in a package of proposed amendments to the Senate bill that he unveiled Thursday. Baker cited National Harbor’s amenities and infrastructure, the site’s ability to draw international visitors and a smaller impact on residential areas.

Sen. Douglas J.J. Peters (D-Prince George’s), lead sponsor of the bill, made an argument similar to Miller’s on Thursday.

“From a business standpoint, I’m concerned if there isn’t competition for a deal that’s in the best interest of Prince George’s County,” said Peters, who chairs the county Senate delegation.

The bill, which is scheduled for a hearing Wednesday, faces considerable hurdles, including mixed views among county lawmakers and staunch opposition from the owner of a planned casino in neighboring Anne Arundel County.