WASHINGTON — To the myriad indignities suffered by Congress, including stagnant legislation, partisan warfare and popularity on a par with petty criminals, add this: the Capitol’s roof is leaking, and there is no money to fix it.

The Capitol dome, the nation’s grandest symbol of federal authority, has been dinged by years of inclement weather, and its exterior is in need of repair.

The dome has 1,300 known cracks and breaks. Water that has seeped in over the years has caused rusting on the ornamentation and staining on the interior of the Rotunda, just feet below the fresco “The Apotheosis of Washington,” which is painted on the Rotunda’s canopy.

Like most of what the federal government is on the hook to fix — highways, bridges and airports — the dome is imperiled both by tough economic times and by a politically polarized Congress. While Senate appropriators have voted to repair the dome, which has not undergone major renovations for 50 years, their House counterparts say there is not money right now. In that way, the dome is a metaphor for the nation’s decaying infrastructure....