1.   But even the best efforts can backfire.

2.   But her efforts may be backfiring with some fellow historians.

3.   But McMaster bravely insisted that the effort had backfired on the Democrats.

4.   But that effort backfired when the officials returned home with tales of extortion of businesses, summary executions, forced recruitment of teen-agers and other guerrilla abuses.

5.   But some warn the effort could backfire.

6.   But the effort backfired.

7.   But these efforts will backfire if children kicked out of these factories drift to more hazardous occupations.

8.   From all accounts, the effort backfired.

9.   If he did take on Gore, would the effort backfire?

10.   If they do not, the effort could well backfire in embarrassment.