Those who campaign for Congress should be open and honest about their faith, their views and what they stand for. In my opinion they should not use their faith or anything else to “garner votes” (though I know this goes on all the time).
If a person is elected, then those he represents have the right to expect that he will act in accordance with the views, beliefs etc. that were stated during the campaign.
However - it is unfair to try to force a candidate to hold to a particular view past a certain point. For while we have the right to expect those running for office and those elected to be honest, they have the right to expect us to trust them.
To answer your question “Should a Catholic be able to be recognized by his(her)behaviors?”, I would say yes. A Catholic politician should be true to the teachings of the Church and act in Love and honesty.
Peace
James