短语讲解：
1. He says many American voters have expressed concern about the Republican nominee.

concern about 使（自己）关心…
例句：She showed great concern about you.
她很为你担心。

2. He said they ’’don’t see him having the commander-in-chief qualities” to deal with complex world problems.

deal with 应付; 对待; 惠顾; 与…交易
例句：They then moved on to deal with the agenda point by point.
然后他们对议程又逐条地进行商议。

3. His opponent, then President George H.W. Bush, also had a trust issue because he agreed to a tax increase after saying at the 1988 Republican convention, “Read my lips. No new taxes.”

agree to 同意， 赞成， 同意照办
例句：I cannot but agree to your decision.
我不得不同意你的决定。