Republicans do not have a mandate from the 2014 election
Twenty years ago, when the Republican Party won the House of Representatives for the first time in forty years, they had a positive mandate from the voters to pursue a legislative agenda. The 2014 mid-term elections might be a stinging rebuke to President Obama, but they are not a mandate for a Republican agenda.
The reason Republicans had a mandate after their 1994 victory was that they campaigned on a national agenda, the Contract with America. The Republican Party set forth a specific set of proposals and promised a vote on each of them. Republican candidates for Congress signed the Contract and promised to help implement it. There was no such national agenda for the 2014 mid-term elections from the Republican Party.
This is why Senator Ted Cruz was wrong when he said now is the time for tax reform and regulatory reform. He is right from a policy standpoint, but there is no mandate from the voters to do that. There is no mandate from the voters because Republicans did not run on a policy agenda. There is a clear mandate to stop Obama's agenda, but not a mandate to advance any specific Republican agenda.
What Republicans need to realize is they did not win the 2014 mid-term election. Democrats lost the election. There is a big difference between the two, and this is the consequences of not setting a national legislative agenda for voters to affirmatively vote for. Republicans need to be careful not to overreach and create a backlash that will hurt the party's chances of capturing the White House in 2016.
Whether not setting a national agenda was a good political strategery or not, the election is over and the strategery was chosen and implemented. If Republicans are to have a national legislative agenda, it will be after the 2016 elections, where the party platform and the nominee's agenda will be debated. If Republicans win that election, they will have a mandate. Right now, there is no mandate other than "stop Obama."