Michael Barone‘s latest Washington Examiner column explains why Thursday created some problems for President Obama and his party, and not just because of a successful Republican presidential debate.

[N]one could respond to an event offstage that may have more immediate impact than the debate. That was the announcement that Senator Chuck Schumer, Senate Democrats’ leader-in-waiting, is voting to disapprove Barack Obama’s deal with Iran. This was apparently leaked by the White House to the Huffington Post during the debate — an even better time to bury news than a pre-holiday-weekend Friday afternoon.

This came just one day after Obama’s disgraceful speech where he likened Republican opponents of the deal to Iran regime supporters chanting “Death to America!” A White House reporter might ask at the next presidential press conference whether Schumer fits into that category.

Administration strategists hoped that Schumer would support the deal or delay a no vote until it was too late to influence others. Instead he announced his position, in a thoughtful and serious statement, as members of Congress fan out to face constituents. Polls show voters are increasingly skeptical for the reason Schumer found pivotal — skepticism about the deal will make Iran’s leaders less hostile to America.

The no votes of Schumer and House Foreign Affairs ranking Democrat Elliot Engel, also announced Thursday, mean there will be a large bipartisan majority against the deal. Maybe even the two-thirds required for disapproval.

That casts a cloud over what Obama regards as his signal foreign policy achievement, even as the Cleveland debates showed the Republican race is not a clown show. A tough Thursday for the president and his party.