Yes, those states rejected the president and liberalism. But other states the Democrats carried embraced both. Now I haven't seen the national numbers as they are probably still being accumulated and totaled. Until I see them it is hard to say especially when the playing ground favored the Republicans by so much. I would say at this time the Republicans did not receive a mandate. That they won states they should have won and lost states they should have lost.
With only one third of the senate up for re-election that doesn't reflect the national mood or as you stated rejection of a political ideology. It just shows which state rejected it and which state embraced it. I think on a national level one can get a better idea by looking at the president approval rating. It too will vary state by state, but nationally it is at 42% with his disapproval at 54%. That alone especially in red states and the light blue states of Iowa and Colorado explain why the Democratic senate candidates lost. The job the president is doing is not well liked and this started in September of last year. For lack of a better phrase, Obama fatigue has set in. The Democrats better hope that it doesn't last into 2016. But the only way Obama can turn that around is to adjust his policies where they are suited to the majority of Americans, not just his base and I do not see him doing that.