Brandon Saad scored his first two goals of the postseason, and Chicago earned its sixth consecutive win despite stretches of lackluster play in the second and third periods. Corey Crawford made 18 saves in another solid performance.
The series opener was tied at 2 in the third period before Patrick Kane scored two of Chicago's final three goals in a 5-2 victory on Friday night.
Game 3 is Tuesday night in Minnesota.
Clayton Stoner and Erik Haula made nice passed to set up McCormick's first playoff goal in three years 2 minutes into the third, trimming Chicago's lead to 2-1. Crawford then batted a potential tying shot from Charlie Coyle over the crossbar.
The Blackhawks eventually regained their composure and turned up the pressure again. Bickell shot the puck off the crossbar on a break with 4:39 to go.
Given a second chance, the physical forward delivered. Marian Hossa and Bickell got loose on another break, and Bickell buried his shot into the upper right corner to extend Chicago's lead to 3-1 at 17:15.
Saad added an empty-net goal as the Blackhawks improved to 16-2 in home playoff games over the last two years. They are 5-0 at the United Center in this postseason.
Chicago played without forward Andrew Shaw, who was out with a lower-body injury. Shaw left the series opener after he was hit hard by Stoner in the first period. He appeared to favor his right side as he made his way off the ice.
Shaw, who had 19 goals and 20 assists in the regular season, is expected to travel with the team to Minnesota. Wild coach Joel Quenneville said he likely would be able to play in Game 3.
Chicago jumped out to a 2-0 lead for the second straight game. Jonathan Toews scored a rebound goal after goalie Ilya Bryzgalov stopped Hossa on a breakaway in the first, and Saad sent a shot over Bryzgalov's right shoulder right after a power play expired in the second.
Haula had a great scoring opportunity on the right side of the net after Crawford lost track of the puck in the first. But Ben Smith got back, and Haula put a drive off the side of the net.
The Wild failed to convert on their only power play after going 0 for 3 with the man advantage in the opener. They went 0 for 17 on the power play when they were eliminated by the Blackhawks in five games in 2013.
Penguins 3, Rangers 0: Kris Letang broke a scoreless tie in the second period and Marc-Andre Fleury made 22 saves for his seventh playoff shutout to lift Pittsburgh to victory over New York, tying the second-round series one game apiece.
Letang's 15th career postseason goal matched Larry Murphy's record for Penguins defensemen. Jussi Jokinen scored during a third-period power play, and Evgeni Malkin added an empty-net goal for the Penguins, who managed a home split in the first two games with the suddenly weary Rangers.
Game 3 is Monday night in New York.
Henrik Lundqvist made 32 saves for New York, but the Rangers mustered little offense while playing their fourth game in six days. New York's limp power play went 0 for 4 and hasn't scored in 29 straight advantages.
The Rangers have lost eight straight Game 2s and have dropped an NHL-record 13 consecutive games when leading in a series.
They had their chances to jump ahead early, only to be let down again by the power play.
Three times in the first 10 minutes New York went to the power play, and three times the Rangers spent two minutes skating around as though they were killing time before getting back to even strength.
Only Lundqvist seemed interested in sending the Rangers back to New York with a commanding 2-0 lead. He was typically brilliant, particularly when Pittsburgh captain Sidney Crosby was on the ice.
The NHL's leading scorer and Hart Trophy finalist is in the midst of a lengthy postseason scoring funk. He began the night without a goal in 12 straight playoff games, a span that included 327 shifts and 275 minutes of ice time. However, the slump has had Crosby's teammates rising to the captain's defense.