Sorry, but it can't be summed up in six words.
It's easy to say that the republicans are in the pockets of some big company.
The Republicans and the Democrats are in the same people's pockets. If some big aerospace factories close, thousands of people lose jobs, and the local representative doesn't get re-elected. The difference between the Republican and the Democrat is that the Republican thinks it's the big company's responsibility to give those people a job, and the Democrat thinks it's the government's responsibility to make sure those workers don't need to worry about whether they have a job or not.
Bottom line, it's always about the voters. Except that most of our citizens of voting age are so cynical about the process, and think it's all about the "money/power/big companies/cronyism" that they stay home and dilute the real power base.
Get off your ass and go vote.
Better yet. Understand what the people you're voting for actually stand for before you go vote. Otherwise you'll be surprised when the guy you voted for to change things starts supporting revoking Miranda rights, and sends more troops to the wars you don't support, and keeps an infamous prison open, and supports off-shore drilling, and signs a massive health care welfare bill into law just like the last guy did, and generally acts like a re-incarnation of George W. Bush, even though the writing was on the wall before the election, and everybody who pointed it out was routinely censored by the internet community.