This is a simple question to answer if you use thought rather than emotion to formulate your answer.
Voters and the general public who consider themselves on the left are very passionate and compassionate, however the things they vote for usually bring about the exact opposite of what the lefty voters want.
A large Federal Government takes away money from productive citizens and gives a little bit to the poor. However, most of the money ends up in the pockets of the rich one way or another. So, we end up with more poor people and a few fat cats in charge. It is taking away the middle class.
The income tax makes it more difficult for poor or middle class people to move out of poverty. The rich have loopholes. The working classes get money taken out of their paychecks so it is more difficult to move out of poverty and more difficult to move to a higher socioeconomic class.
The communism-lovers think that they will be part of the communist ruling class. They are in for a big shock.
Lefties believe in abortion. How the F is that compassionate? Granted there are times when an abortion may be the right answer - health of mother, rape, incest, health of child- but most of the time it would be more compassionate to give birth and give the child to a couple who cannot have children.
Feeding kids school lunches makes sense, however feeding them breakfast lunch and dinner means that the Government has more and more control over everyone's life. Is it compassiionate to want people to be the slave of the government? Hey, I grew up in a liberal household...I've heard the other side.
Liberals talk about discrimination, but they often give preference to people of color who are not as qualified. If two people are equally qualified and one is a minority, I think that you should choose the minority to give them a chance. Liberals also vote according to race. That is the freaking opposite of what MLK wanted.
On the other hand:
Conservatives are more likely to donate money.
Conservatives hate poverty. However, conservatives would rather have you get a job (and be able to keep more of the money you earn) so you can get yourself out of poverty.
Some conservatives know how the government tries to control everything you do when you are on welfare...I once was living in a "welfare household" when I was 16. It sucked.
So, remember that stereotypes can be wrong.