According to the same site, business PAC contributions to the Dems was far beyond that given by labor unions (56% higher). That given to Repubs was 250% higher. This counts neither soft money, which I believe comes overwhelmingly from business interests, nor donations in-kind, again lopsidedly from business --- and if memory serves, soft money is usually a far larger quantity than PAC money.
Finally, to equate the "labor movement" with the AFL-CIO is quite a leap. The extent to which the big unions have been co-opted by business needs a bit of a mention as well, along with the general distance of the leadership structure from the average worker.
Bill