(CNN) -- -- U.S. President Barack Obama is about to crash into Congress and like bystanders on the roadside we can all see the collision coming.
The point of contact is November 2 when Americans go to the polls to elect new lawmakers in Washington. "It's going to make a huge difference as to whether we're going to be able to move our agenda forward for the next couple of years," Obama said as he campaigned this week.
There is a cycle to American politics. Congressional elections are held midway through every four-year presidential term and voters generally take the opportunity to express their frustration with whichever party is in power. This time, the Democrats hold in the White House and both houses of Congress, so they will be the ones to take the punishment.
Obama has already had trouble in the Senate because the Democrats don't have a big enough majority there to override opposition from Republican lawmakers. The Democrats are expected to lose a few seats so that majority will shrink or maybe disappear .
The House of Representatives now has a dependably big and commanding Democratic majority. But the Democrats look very likely to lose dozens of seats so their House majority is in even greater peril.
"In midterm elections, the president's party loses on average 24 seats in the House and it loses on average three to four Senate seats," said political scientist Larry Sabato.
"My sense of this is that at a minimum, I do mean minimum, you can double those numbers for November."
Republicans can read the polls and feel the momentum swing their way. They are promising dramatic changes -- to cut taxes and spending, and to repeal Obama's most important initiative, the reform of U.S. healthcare.
"So imagine how much more difficult a job the president will face," said CNN Deputy Political Director Paul Steinhauser.
"The next two years could bring a stalemate to Capitol Hill, which may not be broken until voters go to the polls again in 2012."
In other words, there could be one big crash followed by two years of waiting for a way to repair the damage.