Dallas Ambush: Five Dallas police officers were killed and six wounded in a coordinated sniper attack near the end of a peaceful protest last night against police killings of black men in Louisiana and Minnesota. Gunshots echoed off the glass towers of downtown Dallas as the protesters ran for their lives.

“There has been a vicious, calculated and despicable attack on law enforcement,” President Obama said from Warsaw after a meeting with European leaders.

Police Chief David Brown said that at least four shooters had set up a triangulated ambush, clearly targeting only police officers. Three suspects, including a woman, are in custody and it’s been reported that police were negotiating for the surrender of a fourth.

The suspects are reported to be refusing to cooperate. So far, investigators don’t know whether there is any direct connection between the shooting and the demonstration.

Black Lives: The Dallas ambush is an explosive end to a week of tension over policing and black citizens.

After the fatal shooting of a black driver in a traffic stop, Minnesota Gov. Mark Dayton bluntly asked in a press conference, “Would this have happened if the driver were white, if the passengers were white?” Answering his own question he added, “I don’t think it would have.”

Getting off Air Force One in Warsaw earlier last night, President Obama joined the condemnation of the police shootings of two black men on two successive days. A somber and reflective Obama said, “To be concerned about these issues is not political correctness. It’s just being an American,” He went on, “And to recognize the reality that we got some tough history and we haven’t gotten through that history yet.”

Philando Castile, 32, was killed in Falcon Heights, Minn. in the car also occupied by his fiancée and her four-year-old daughter. Alton Sterling, 37, a father of five, was wrestled to the ground and shot dead by police officers outside a convenience store in Baton Rouge.

As protesters marched here at home, Obama said in Poland, “I would just ask those who question the sincerity or the legitimacy of protests and vigils and expressions of outrage, who somehow label those expressions of outrage as ‘political correctness,’ I just ask folks to step back and think, what if this happened to somebody in your family? How would you feel?”

The Count: The Guardian counts 566 people shot and killed by police in the US so far this year. Of those, 136 have been black and 88 Hispanic/Latino. Eighty-two of the 566 were unarmed.

The five Dallas police officers bring to 24 the number of police off cars killed this year by hostile gunfire.

Politi-Salad: Bernie Sanders is expected to endorse Hillary Clinton sometime next week — Just coincidentally, Hillary Clinton announced she will pursue a policy of debt-free college for everyone — The NY Times floats the theory about Donald Trump winning the presidency out of sheer competitiveness and then declining to serve. Popped with the question leaving Trump Tower, the Donald said, “I’ll let you know how I feel about it after it happens” — In a private meeting with 41 Senate Republicans yesterday that was supposed to be a peace parley and exchange of ideas, Trump threatened one senator and called another “a loser.” Sen. Jeff Flake of Arizona said he could not support Trump because of his statements about Mexicans. Trump threatened that he would see that Flake is not re-elected this year. Flake informed Trump he’s not up for re-election this year.

Before Hillary: Voting in Britain’s Conservative Party has narrowed the possibilities down to two women who might succeed David Cameron after he leaves 10 Downing Street. They are Theresa May, the home secretary who wanted to stay in the European Union, and Andrea Leadsom, minister for energy, who promised to guide Britain out of the EU: “Huge opportunity for our country!” That’s pronounced “Yuge.”

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