WASHINGTON – Republicans lashed out at President Barack Obama and senior administration officials over their evolving description of the deadly Sept. 11 attack on the U.S. Consulate in Libya, a late campaign-season broadside challenging the veracity and leadership of an incumbent on the upswing.

Desperate to reverse the apparent trajectory of the White House race, Republicans sense a political opportunity in Obama’s reluctance to utter the words “terrorist attack” as well as the varying explanations emerging from the administration about the assault in Benghazi that killed Ambassador Chris Stevens and three other Americans.

Talk of Watergate-style scandal, stonewalling and cover-up echoed in the GOP ranks Thursday, from the head of the party to members of Congress to Mitt Romney’s campaign staff. This full-throated criticism comes five days before the first debate between Obama and Romney, with Republicans determined to cast the president as dishonest and ineffectual on both foreign and domestic policy.