The bad news for Donald Trump is, recent polling indicates the investigations into Hillary Clinton’s response to the terror attack in Ben­ghazi and her use of a private email server while secretary of state failed to deliver the desired knockout punch — but it’s not over.

The Republican presidential front-runner can still damage Clinton’s reputation and trustworthiness numbers by focusing on the brewing Clinton Foundation scandal.

Although news that the State Department will reopen its investigation into Clinton’s handling of classified material will keep the email scandal front and center, Trump would be wise to shift his focus.

The Clinton Foundation — in existence since 2001 — has received millions of dollars in contributions from countries with complicated diplomatic and military relationships with the United States.

Countries including Kuwait, Qatar and Oman.

In addition to that, there’s the seemingly sketchy connection between the foundation, former president Bill Clinton, Hillary Clinton and Switzerland’s largest bank, UBS AG.

According to a recent Wall Street Journal story, a few weeks after Clinton was sworn in as secretary of state in early 2009, she resolved an issue the bank was having with Internal Revenue Service officials who were suing to get the identities of Americans with secret accounts.

Within months, Secretary Clinton announced a settlement. The bank turned over information on 4,450 accounts, which represented just a fraction of the nearly 52,000 requested by the IRS.

And though Clinton’s intervention was viewed by many as highly unusual, the story gets even more juicy.

Prior to 2008, UBS AG gave less than $60,000 to the Clinton Foundation. From 2009-2014 the contributions totaled in excess of $500,000. A nearly 900% increase.

As if that wasn’t enough, the bank paid Bill Clinton $1.5 million to take part in a series of question-and-answer sessions with UBS Wealth Management Chief Executive Bob McCann.

This “fee” makes UBS the largest single corporate source of speech income for Clinton since leaving the White House. That reeks of quid pro quo.

These are the stories that Trump and his campaign should hammer home if he wants to plant that seed of doubt that Clinton is not trustworthy enough to be our next commander in chief.

John Sapochetti is co-host of “Boston Herald Drive,” heard weekday mornings 6-9 on Boston Herald Radio. Follow him on Twitter @johnsap25.