Yes.
One is the encumbant, vote against that one.
One is the opponent, vote for that one.
Here's the deal, politicians that aren't in office have no power, no fun, and no reason to live. So they desparately seek "being in office." (often times by making silly promises but that is another comment)
Now if you have a choice between a giant douche (GD) and a turd sandwich (TS) and you always vote against the incumbent. Then one of them (and often both of them) will start changing their behavior so that if they get into office they would stay there. You have the power to modify their behavior, use it.
Many elections are won by a difference of less than 10%. So if the 10% of the electorate can choose to play this game (is there 1 in 10 intelligent people in your district?) they will create a better government for everyone.
They use a simple rule:
1) Person in office is doing a 'good' job? Vote for him
2) Person in office is doing a 'bad' job? Vote against him
It doesn't matter who is running against them or their qualifications. Because, like evolution, this system has its own fitness function (the 10% group think they are doing a 'good' job) which anyone running will quickly come to realize determines if they stay in office.
You can even start a campaign "I'm one of the 10% making a better government for you." And when you talk to your elected officials, and candidates for office, let them know the criteria you are using to determine 'good' and what it will take to stay in office.
The only way to defeat this system is with outright vote fraud which, as intelligent people, you should be able to help the election commission detect. No amount of special interests, no amount of campaign money, no amount of lying to the stupid people will work.
So use this system and always vote. It always matters.