Sen. Tim Johnson (D-S.D.) (AP Photo/Argus Leader, Jay Pickthorn)

A third Democrat said this week that  he will oppose the nomination of  Long Island hotel executive George Tsunis – who bundled or contributed more than $1.3 million for President Obama in 2012 – to be ambassador to Norway.

Sen. Tim Johnson (D-S.D.) on Thursday joined Minnesota Democratic Sens. Amy Klobuchar and Al Franken in opposing the nomination, telling the Sioux Falls  Argus Leader  that he felt “Mr. Tsunis’ performance at his confirmation hearing did not give me confidence in his knowledge of Norway or his ability to be an effective ambassador.”

Tsunis, founder and CEO of Chartwell Hotels, stumbled badly at that hearing in January, when asked about anti-immigrant sentiment in Norway. He also referred to Norway’s “president,” when, as a constitutional monarchy, that nation doesn’t have a president.

The Norwegian press was insulted and outraged by Tsunis’s responses. Many Norwegian-Americans, especially influential in the upper Midwest, apparently were equally upset.

With 55 Democratic votes in the Senate, Tsunis, assuming all Republicans vote against him, is now down to 52 votes if the remaining Democrats vote for him — not a foregone conclusion at this point.

The State Department, last time we checked, was still backing Tsunis for the post. Any more defections, though. . .