What do the following pairs of  words have in common?

FIRECRACKER & MISCONSTRUING
BLOCKBUSTER & DOOHICKEY
SHUNTING & BESPECKLED
PROLIFERATION & CLIMBING
HEARTSTRINGS & CONSCIENCES

HINT:
Hidden in each clue are two words which make up a common phrase.

Answers:

firecRACKer & misconstRUINg
bLOCKbuster & doohicKEY
sHUNTing & besPECKled
proLIFEration & cLIMBing
heARTStrings & conSCIENCES