WPF pass a DataContext to my UserControl inside a DataTemplate

I have a TabControl with two ContentTemplates:

<TabControl ItemsSource="{Binding Tabs}" ContentTemplateSelector="{StaticResource TabSelector}">
    <TabControl.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <TextBlock Text="{Binding TabName}" HorizontalAlignment="Center" />
            </StackPanel>
        </DataTemplate>
    </TabControl.ItemTemplate>
</TabControl>

And my two templates are two user controls:

<UserControl.Resources>        
    <ResourceDictionary>
        <DataTemplate x:Key="UserListTemplate">
            <uc:UserList />
        </DataTemplate>

        <DataTemplate x:Key="UserContentTemplate">
            <uc:User />
        </DataTemplate>

        <uc:TabSelector x:Key="TabSelector" UserListTemplate="{StaticResource UserListTemplate}" UserContentTemplate="{StaticResource UserContentTemplate}" />
    </ResourceDictionary>
</UserControl.Resources>        

I'm setting the DataContext in the XAML:

<UserControl.DataContext>
    <local:ViewUsers />
</UserControl.DataContext>

The TabControl bind is working, showing all the tabs as I add/remove from the collection, but how do I get the DataContext in my UserControls? The DataContext is always null when the UserControl is started.