In the recent election, a country’s voters overwhelmingly chose Adler over Burke.
Information
Adler beat Burke in a landslide.
Voters knew that Burke offered better solutions to most of the country's problems and that Burke has a long, reputable track record in government.
pivot (However) It was well known that Burke's environmental policy favored polluters, whereas Adler proposed a strict environmental crackdown.
Evaluate
When the final idea in an Inference paragraph is introduced with some Pivot word, it usually means that the correct answer is what you get by integrating that last idea with what came before.
In this case, the last idea is telling us the one bad thing about Burke so far. We heard Burke badly lost the election despite having better solutions to most problems and having a great track recording in government.
So this negative idea about Burke (his environmental policy favored the most dangerous polluter) would be our only speculation for why Burke lost the election.
Goal
It is speculative, not for sure (but this is Most Supported, not Must Be True), but let's look for something like