Wall Street was apparently not happy to learn that a key lawmaker in the Senate is prepared to crack down on GSE portfolios. But some analysts are still confident that Fannie Mae and Freddie Mac will stave off unfavorable legislation. Evidence that the political fortunes of Fannie and Freddie can be closely linked with their stock prices could be gathered from events that took place late last month. On June 21, Fannie’s stock hit a…