WASHINGTON — Add this to the lore of championship ceremonies at the White House: President Bush believes in the Jessica Simpson jinx.

Bush, a Texas guy, lauded the Giants yesterday for winning the Super Bowl. Any football championship is big to the team and its fans, but this one was all the sweeter because it required a riveting, comeback effort against the New England Patriots, who were heavily favored and had not lost all year.

The president noted that along the way the Giants vanquished a team from his home state — the Dallas Cowboys. Many Dallas fans pinned their team’s surprise playoff loss not on the Giants, but on Simpson. Seems the singer-actress was accused of being a distraction to her boyfriend, Dallas quarterback Tony Romo.

Apparently, Bush bought in.

“I’m a good sport,” Bush said at the South Lawn ceremony. “We’re going to send Jessica Simpson to the Democrat National Convention.”

Everything is political.

Even Bush, an early-to-bed leader, stayed up late that February night to watch the Giants pull ahead and hang on.

He didn’t skimp on the superlatives. “It turned out to be really one of the great, legendary football games in our nation’s history,” he said yesterday.

With players and coached gathered behind him on a comfortable spring day, Bush praised the team for its resilience.

“You won the gratitude of your fans. The New York Giants fans love these Giants,” Bush said.