WASHINGTON (AP) — The Iran nuclear deal strongly backed by President Barack Obama and just as ardently opposed by the GOP is now on track to get through Congress.

In the Senate, Democratic supporters can claim a decisive 34 votes in favor after Sen. Barbara Mikulski of Maryland said she will vote for the pact.

That will allow backers to uphold Obama's veto, if necessary, of a resolution of disapproval Republicans are trying to pass this month.

Senate Majority Leader Mitch McConnell grudgingly acknowledges that his side will not be able to block the deal, which he says leaves Iran "with a threshold nuclear capability."

White House press secretary Josh Earnest calls the growing support a validation of Obama's effort to make sure senators understand the deal.